I cant access help file under extend section
Warning: Trying to access array offset on value of type null in Drupal\tac_lite\Plugin\Derivative\SchemeLocalTask->getDerivativeDefinitions() (line 20 of /var/www/html/web/modules/contrib/tac_lite/src/Plugin/Derivative/SchemeLocalTask.php)
#0 /var/www/html/web/core/includes/bootstrap.inc(347): _drupal_error_handler_real(2, 'Trying to acces...', '/var/www/html/w...', 20)
#1 /var/www/html/web/modules/contrib/tac_lite/src/Plugin/Derivative/SchemeLocalTask.php(20): _drupal_error_handler(2, 'Trying to acces...', '/var/www/html/w...', 20)
#2 /var/www/html/web/core/lib/Drupal/Component/Plugin/Discovery/DerivativeDiscoveryDecorator.php(101): Drupal\tac_lite\Plugin\Derivative\SchemeLocalTask->getDerivativeDefinitions(Array)
#3 /var/www/html/web/core/lib/Drupal/Component/Plugin/Discovery/DerivativeDiscoveryDecorator.php(87): Drupal\Component\Plugin\Discovery\DerivativeDiscoveryDecorator->getDerivatives(Array)
#4 /var/www/html/web/core/lib/Drupal/Core/Plugin/DefaultPluginManager.php(285): Drupal\Component\Plugin\Discovery\DerivativeDiscoveryDecorator->getDefinitions()
#5 /var/www/html/web/core/lib/Drupal/Core/Plugin/DefaultPluginManager.php(175): Drupal\Core\Plugin\DefaultPluginManager->findDefinitions()
#6 /var/www/html/web/core/lib/Drupal/Core/Menu/LocalTaskManager.php(181): Drupal\Core\Plugin\DefaultPluginManager->getDefinitions()
#7 /var/www/html/web/core/lib/Drupal/Core/Menu/LocalTaskManager.php(206): Drupal\Core\Menu\LocalTaskManager->getDefinitions()
#8 /var/www/html/web/core/lib/Drupal/Core/Menu/LocalTaskManager.php(290): Drupal\Core\Menu\LocalTaskManager->getLocalTasksForRoute('tac_lite.admini...')
#9 /var/www/html/web/core/lib/Drupal/Core/Menu/LocalTaskManager.php(358): Drupal\Core\Menu\LocalTaskManager->getTasksBuild('tac_lite.admini...', Object(Drupal\Core\Cache\CacheableMetadata))
#10 /var/www/html/web/core/lib/Drupal/Core/Menu/Plugin/Block/LocalTasksBlock.php(95): Drupal\Core\Menu\LocalTaskManager->getLocalTasks('tac_lite.admini...', 0)
#11 /var/www/html/web/core/modules/block/src/BlockViewBuilder.php(171): Drupal\Core\Menu\Plugin\Block\LocalTasksBlock->build()
#12 [internal function]: Drupal\block\BlockViewBuilder::preRender(Array)
#13 /var/www/html/web/core/lib/Drupal/Core/Security/DoTrustedCallbackTrait.php(101): call_user_func_array(Array, Array)
#14 /var/www/html/web/core/lib/Drupal/Core/Render/Renderer.php(772): Drupal\Core\Render\Renderer->doTrustedCallback(Array, Array, 'Render #pre_ren...', 'exception', 'Drupal\\Core\\Ren...')
#15 /var/www/html/web/core/lib/Drupal/Core/Render/Renderer.php(363): Drupal\Core\Render\Renderer->doCallback('#pre_render', Array, Array)
#16 /var/www/html/web/core/lib/Drupal/Core/Render/Renderer.php(435): Drupal\Core\Render\Renderer->doRender(Array)
#17 /var/www/html/web/core/lib/Drupal/Core/Render/Renderer.php(201): Drupal\Core\Render\Renderer->doRender(Array, false)
#18 /var/www/html/web/core/lib/Drupal/Core/Template/TwigExtension.php(479): Drupal\Core\Render\Renderer->render(Array)
#19 /var/www/html/web/sites/default/files/php/twig/62caa02706664_page.html.twig_3YwR0rXRwy7IL5zpJjxrHUluh/Y5cRKJvxdOTAnkJ6CvEwZfMJkh7gNHQGeossRaqOcIQ.php(47): Drupal\Core\Template\TwigExtension->escapeFilter(Object(Drupal\Core\Template\TwigEnvironment), Array, 'html', NULL, true)
#20 /var/www/html/vendor/twig/twig/src/Template.php(405): __TwigTemplate_6a245e8de4e93b300d7ed51ccc99bb6812a72b4b0c8a1e3ea943eeb98327d1f0->doDisplay(Array, Array)
#21 /var/www/html/vendor/twig/twig/src/Template.php(378): Twig\Template->displayWithErrorHandling(Array, Array)
#22 /var/www/html/vendor/twig/twig/src/Template.php(390): Twig\Template->display(Array)
#23 /var/www/html/web/core/themes/engines/twig/twig.engine(55): Twig\Template->render(Array)
#24 /var/www/html/web/core/lib/Drupal/Core/Theme/ThemeManager.php(384): twig_render_template('core/themes/cla...', Array)
#25 /var/www/html/web/core/lib/Drupal/Core/Render/Renderer.php(422): Drupal\Core\Theme\ThemeManager->render('page', Array)
#26 /var/www/html/web/core/lib/Drupal/Core/Render/Renderer.php(201): Drupal\Core\Render\Renderer->doRender(Array, false)
#27 /var/www/html/web/core/lib/Drupal/Core/Template/TwigExtension.php(479): Drupal\Core\Render\Renderer->render(Array)
#28 /var/www/html/web/sites/default/files/php/twig/62caa02706664_html.html.twig_wY46ZmGqBZhstB3SjfOlGCgPn/zZRNemI6q-zjpF_gCpRO5LnPqAnUfd42cRt4atDjxdk.php(86): Drupal\Core\Template\TwigExtension->escapeFilter(Object(Drupal\Core\Template\TwigEnvironment), Array, 'html', NULL, true)
#29 /var/www/html/vendor/twig/twig/src/Template.php(405): __TwigTemplate_7958435c65e41827709e4668fe1767569c130c39854cf4832e1605b312f840ed->doDisplay(Array, Array)
#30 /var/www/html/vendor/twig/twig/src/Template.php(378): Twig\Template->displayWithErrorHandling(Array, Array)
#31 /var/www/html/vendor/twig/twig/src/Template.php(390): Twig\Template->display(Array)
#32 /var/www/html/web/core/themes/engines/twig/twig.engine(55): Twig\Template->render(Array)
#33 /var/www/html/web/core/lib/Drupal/Core/Theme/ThemeManager.php(384): twig_render_template('core/themes/cla...', Array)
#34 /var/www/html/web/core/lib/Drupal/Core/Render/Renderer.php(422): Drupal\Core\Theme\ThemeManager->render('html', Array)
#35 /var/www/html/web/core/lib/Drupal/Core/Render/Renderer.php(201): Drupal\Core\Render\Renderer->doRender(Array, false)
#36 /var/www/html/web/core/lib/Drupal/Core/Render/MainContent/HtmlRenderer.php(162): Drupal\Core\Render\Renderer->render(Array)
#37 /var/www/html/web/core/lib/Drupal/Core/Render/Renderer.php(564): Drupal\Core\Render\MainContent\HtmlRenderer->Drupal\Core\Render\MainContent\{closure}()
#38 /var/www/html/web/core/lib/Drupal/Core/Render/MainContent/HtmlRenderer.php(163): Drupal\Core\Render\Renderer->executeInRenderContext(Object(Drupal\Core\Render\RenderContext), Object(Closure))
#39 /var/www/html/web/core/lib/Drupal/Core/EventSubscriber/MainContentViewSubscriber.php(90): Drupal\Core\Render\MainContent\HtmlRenderer->renderResponse(Array, Object(Symfony\Component\HttpFoundation\Request), Object(Drupal\Core\Routing\CurrentRouteMatch))
#40 [internal function]: Drupal\Core\EventSubscriber\MainContentViewSubscriber->onViewRenderArray(Object(Symfony\Component\HttpKernel\Event\ViewEvent), 'kernel.view', Object(Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher))
#41 /var/www/html/web/core/lib/Drupal/Component/EventDispatcher/ContainerAwareEventDispatcher.php(142): call_user_func(Array, Object(Symfony\Component\HttpKernel\Event\ViewEvent), 'kernel.view', Object(Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher))
#42 /var/www/html/vendor/symfony/http-kernel/HttpKernel.php(163): Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch(Object(Symfony\Component\HttpKernel\Event\ViewEvent), 'kernel.view')
#43 /var/www/html/vendor/symfony/http-kernel/HttpKernel.php(80): Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object(Symfony\Component\HttpFoundation\Request), 1)
#44 /var/www/html/web/core/lib/Drupal/Core/StackMiddleware/Session.php(58): Symfony\Component\HttpKernel\HttpKernel->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#45 /var/www/html/web/core/lib/Drupal/Core/StackMiddleware/KernelPreHandle.php(48): Drupal\Core\StackMiddleware\Session->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#46 /var/www/html/web/core/modules/page_cache/src/StackMiddleware/PageCache.php(106): Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#47 /var/www/html/web/core/modules/page_cache/src/StackMiddleware/PageCache.php(85): Drupal\page_cache\StackMiddleware\PageCache->pass(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#48 /var/www/html/web/core/lib/Drupal/Core/StackMiddleware/ReverseProxyMiddleware.php(48): Drupal\page_cache\StackMiddleware\PageCache->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#49 /var/www/html/web/core/lib/Drupal/Core/StackMiddleware/NegotiationMiddleware.php(51): Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#50 /var/www/html/vendor/stack/builder/src/Stack/StackedHttpKernel.php(23): Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#51 /var/www/html/web/core/lib/Drupal/Core/DrupalKernel.php(709): Stack\StackedHttpKernel->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#52 /var/www/html/web/index.php(19): Drupal\Core\DrupalKernel->handle(Object(Symfony\Component\HttpFoundation\Request))
#53 {main}