I use the Joblin webclipper to send it to my notes. There is no bookmarks or saving on the websites yet. You could copy the URL (below every comment "more"...), and then paste it into Mastodon and bookmark it there. I prefer all my bookmarks and notes in Joplin though.
Added: example - adding the "more" URL to Fediverse into the search of my Mastodon app and bookmarking it