Use the points in checkout and you have this in PHP 8:
Notice: Only variables should be passed by reference in Drupal\commerce_user_points\Plugin\Commerce\CheckoutPane\CommerceUserPoints->submitPaneForm() (line 318 of modules/contrib/commerceuserpoints/src/Plugin/Commerce/CheckoutPane/CommerceUserPoints.php).
Drupal\commerce_user_points\Plugin\Commerce\CheckoutPane\CommerceUserPoints->submitPaneForm(Array, Object, Array) (Line: 610)
Drupal\commerce_checkout\Plugin\Commerce\CheckoutFlow\CheckoutFlowWithPanesBase->submitForm(Array, Object)
call_user_func_array(Array, Array) (Line: 114)
Drupal\Core\Form\FormSubmitter->executeSubmitHandlers(Array, Object) (Line: 52)
Drupal\Core\Form\FormSubmitter->doSubmitForm(Array, Object) (Line: 597)
Drupal\Core\Form\FormBuilder->processForm('commerce_checkout_flow_egm_checkout_flow', Array, Object) (Line: 325)
Drupal\Core\Form\FormBuilder->buildForm(Object, Object) (Line: 224)
Drupal\Core\Form\FormBuilder->getForm(Object, 'order_information') (Line: 143)
Drupal\commerce_checkout\Controller\CheckoutController->formPage(Object)
call_user_func_array(Array, Array) (Line: 123)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 580)
Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 124)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext(Array, Array) (Line: 97)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 169)
Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 1) (Line: 81)
Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 58)
Drupal\Core\StackMiddleware\Session->handle(Object, 1, 1) (Line: 48)
Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 1, 1) (Line: 106)
Drupal\page_cache\StackMiddleware\PageCache->pass(Object, 1, 1) (Line: 85)
Drupal\page_cache\StackMiddleware\PageCache->handle(Object, 1, 1) (Line: 48)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 51)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 23)
Stack\StackedHttpKernel->handle(Object, 1, 1) (Line: 718)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)
Fixed
9.0
Code
Changes are added now in 3.0.x branch, Thanks for the patch @saurabhkanva.
Automatically closed - issue fixed for 2 weeks with no activity.