Need help freeing up space on Nextcloud server.

First I couldn't access the trash bin in one of my accounts but now I can't log in at all. I think the trash bin needs to be cleared and the only way to do that is probably through SSH somehow. I need someone to walk me through how to accomplish this if possible. Also, I need to find out if it's possible to configure a setting which limits the time a deleted file can exist in the trashbin. We can use TeamViewer or AnyDesk for remote access if needed.