Ao3 Bookmarks - Blog Posts

I need help with AO3 bookmarks

Ok so, do you remember the small pole I did some days ago about starting having bookmarks in case someone ask me to rec them some fics? Well... It turned out like this

But now I have a problem with organizing them, mostly 2 problems, one with thags and one with collections.

I can't figure out how to put personalized tags that don't appear in the list of alredy existing tags, and I can't figure out how to put those that aren't on the list

My other problem it's that I can't understand how collections works, I tried making a private one to organize bookmarks but I can't add those bookmarks

So... I need help to figure them out