as git mergetool

Don't like using VSCode merge conflicts resolution? Try WebStorm's instead.

or any other Jetbrains IDE. If you don't want to buy Webstorm's licence try PyCharm Community Edition instead.

Open your Jetbrains Toolkit and enable generation of shell scripts. Provided the folder that exists in your $PATH. I've used /usr/local/bin.

Open ~/.gitconfig file (it should be in your home directory) in your favourite editor and add this configuration

[merge]
  tool = webstorm
[diff]
  tool = webstorm
[mergetool "webstorm"]
  cmd = webstorm merge $LOCAL $REMOTE $BASE $MERGED --wait
  trustExitCode = true
[difftool "webstorm"]
  cmd = webstorm diff $LOCAL $REMOTE --wait
  trustExitCode = true

This will use WebStorm as your default mergetool and difftool.

Note: If you're using different Jetbrains IDE use it's name instead of webstorm. For example, for PyCharm:

[merge]
  tool = pycharm
[mergetool "pycharm"]
  cmd = pycharm merge $LOCAL $REMOTE $BASE $MERGED --wait

When you encounter merge conflicts just run git mergetool to open up WebStorm. After youre done resolving conflicts just close the app and it will go to the next conflict.