FR/QUESTION: Close ISSUE after merging (n)linked pull requests

I need to make a issue look as a Sprint, and that the issue gets closed when all the linked PR’s are merged.

The project structure is
HEAD_REPO => REPO1, REPO2 => PR(in either repo1 or repo2)

so I create an issue in head repository to follow a pull request in each subrepository, when both pull requests are merged, I would like the issue to auto close.

is this possible now using keywords in the issue description?, if it itsn’t, can it be implemented?

thanks in advance