Deleting and reinstalling QGIS

I have a problem with QGIS as here Previous question. I think QGIS Temporal is corrupted and the only way to correct is to uninstall and reinstall QGIS (QGIS 3.16.1 Ubuntu 20.04). However if I try this via Ubuntu Software I get the error

Unable to remove "QGIS Desktop: The following packages have unmet
dependencies

but no packages are listed. Is there a way to remove QGIS or reinstall/repair via Terminal please?
It would be nice if people were intent on answering questions rather than nitpicking wording