As mentionned in https://help.github.com/en/github/managing-your-work-on-github/linking-a-pull-request-to-an-issue , I set Resolves keyword but it does not closes the issue automatically : https://github.com/moueza/4668271-developpez-des-applications-web-avec-angular/issues/21
Hey! You are using the correct syntax to close/resolve the issue. However, that syntax needs to be provided in a Pull Request, not just a commit. This concept requires a pull request since it triggers an event on the GitHub back end when it is merged which closes all issues mentioned appropriately.
"You can link a pull request to an issue to show that a fix is in progress and to automatically close the issue when the pull request is merged."
I hope this helps!
If you'd like to stick to commit messages you can use a bunch of keywords including "closes", but the commit must be pushed into the master branch to actually close the issue.