Basic question re searching by tags

I have an extremely basic question. I have imported my notes into Joplin and now have several hundred tags as well as around 4,000 notes in the app. I’d like to be able to search my tags, or to search for a note by tag. E.g. if I have a note titled Joplin and another one titled Joplin2, and both are tagged “note-app”, I’d like to be able to find them by searching for the tag “note-app”.

In various online posts here and in the issues tracker, I see people referring to a tag: syntax. I assume this means I should be able to find the notes in my example by typing tag:note-app or tag:note etc. But this doesn’t work. This syntax also isn’t listed in the description of search on the website.

Is there a way to do this? Thanks for all the hard work!