1. Create git patch file: After making changes to source code, write contents of git diff to a file:

   git diff [--cached] [<SOURCE_FILE_SUBSET>] > <PATCH_FILE_PATH>
   

2. Apply the patch file in another branch where needed: git apply <PATCH_FILE_PATH>

References:

• https://www.specbee.com/blogs/how-create-and-apply-patch-git-diff-and-git-apply-commands-your-drupal-website