@saurabhkanva,
When I run the command
phpcs --standard=Drupal --extensions=php,module,inc,install,test,profile,theme,css,info,txt,md,yml
for you module
FILE: /var/www/html/web/modules/contrib/custom_metatag/src/Form/CustomMetatagForm.php
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FOUND 1 ERROR AFFECTING 1 LINE
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8 | ERROR | [x] Use statements should be sorted alphabetically. The first wrong one is Drupal\Core\Url.
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PHPCBF CAN FIX THE 1 MARKED SNIFF VIOLATIONS AUTOMATICALLY
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FILE: /var/www/html/web/modules/contrib/custom_metatag/custom_metatag.module
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FOUND 17 ERRORS AFFECTING 9 LINES
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1 | ERROR | [x] Missing file doc comment
1 | ERROR | [x] The PHP open tag must be followed by exactly one blank line
12 | ERROR | [x] No space found before comment text; expected "// check if current page has any metadata" but found "//check if current page has any metadata"
12 | ERROR | [x] Inline comments must start with a capital letter
12 | ERROR | [x] Inline comments must end in full-stops, exclamation marks, question marks, colons, or closing parentheses
16 | ERROR | [x] Equals sign not aligned with surrounding assignments; expected 1 space but found 2 spaces
70 | ERROR | [x] Expected 1 space after FOREACH keyword; 0 found
83 | ERROR | [x] Expected 1 space between "'nofollow'" and double arrow; 0 found
83 | ERROR | [x] Expected 1 space between double arrow and "'nofollow'"; 0 found
83 | ERROR | [x] Expected 1 space before "=>"; 0 found
83 | ERROR | [x] Expected 1 space after "=>"; 0 found
89 | ERROR | [x] There must be exactly one blank line before the tags in a doc comment
89 | ERROR | [ ] Missing parameter comment
90 | ERROR | [ ] Missing parameter comment
92 | ERROR | [ ] Invalid function name, expected get_metag_tag_entity but found getMetagTagEntity
92 | ERROR | [ ] All functions defined in a module file must be prefixed with the module's name, found "getMetagTagEntity" but expected "custom_metatag_getMetagTagEntity"
95 | ERROR | [x] Expected 1 newline at end of file; 0 found
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PHPCBF CAN FIX THE 13 MARKED SNIFF VIOLATIONS AUTOMATICALLY
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FILE: /var/www/html/web/modules/contrib/custom_metatag/custom_metatag.info.yml
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FOUND 1 ERROR AFFECTING 1 LINE
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7 | ERROR | [x] Expected 1 newline at end of file; 0 found
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PHPCBF CAN FIX THE 1 MARKED SNIFF VIOLATIONS AUTOMATICALLY
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FILE: /var/www/html/web/modules/contrib/custom_metatag/custom_metatag.install
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FOUND 3 ERRORS AND 2 WARNINGS AFFECTING 5 LINES
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3 | ERROR | [ ] Missing short description in doc comment
7 | WARNING | [x] Unused use statement
10 | ERROR | [x] Doc comment short description must end with a full stop
25 | WARNING | [ ] Format should be "* Implements hook_foo().", "* Implements hook_foo_BAR_ID_bar() for xyz_bar().",, "* Implements hook_foo_BAR_ID_bar() for xyz-bar.html.twig.", "* Implements
| | hook_foo_BAR_ID_bar() for xyz-bar.tpl.php.", or "* Implements hook_foo_BAR_ID_bar() for block templates."
30 | ERROR | [x] Expected 1 newline at end of file; 0 found
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PHPCBF CAN FIX THE 3 MARKED SNIFF VIOLATIONS AUTOMATICALLY
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I created Patch for the above error
Hope you value my time and efforts.
Thank You !!