Limit concurrency on jobs triggered on pull requests from forks

Hi,

I was reffered to the concurrency option by the github staff to cancel jobs which are trigerred on pull requests on older pushes. I am using currently the cancel workflow action. Does the concurrency option work if the pull request was opened from a trigger. If yes, how does it work? The default github access token does not seem to have the required authentication to cancel pull requests from a fork.
This should be documented anyway.

Thanks

According to github support team it should work across forks.