Hello Matteo, unfortunately, as said on the add-on main / description page, there is no management / display of bookmark tags, keywords, description field possible as Firefox does not expose those fields through its Web Extension API's.

This is a long open bug to FF (3 years) -> https://bugzilla.mozilla.org/show_bug.cgi?id=1225916

Until they are made is available by FF, it won't be possible to manage them in BSP2.