Which rights are needed to ensure editing an M2M field works properly?

I have an M2M relation that displays correctly in the editor for the admin user:

For user with limited rights, I don’t get those two buttons. I can’t post a screenshot of it due to a limitation on the number of images I can add.

Which rights should I configure to ensure the ‘Add Existing’ button shows up?

Hello,
A M2M is a combination of 3 collections, make sure the user has create access to all 3 of them. It should work, if still doesn’t then probably the issue is related to caching, to solve that you will have to restart the Directus.

Even when granting full read access to the junction table event_event_category and the related model table event_category, the user still doesn’t see an ‘Add Existing’ button:

Any logs I can examine to bring us closer to the problem source?

Just realized you said create access, not read access :person_facepalming: Fixed, thanks!