add to watchlist "where to watch" filters?

i vaguely remember there being a way to add what platforms YOU specifically watch on, so that they're included on the "where to watch" filter in a list - specifically your watch list. i can't seem to find this option, so i'm coming here to see if i just dreamed this up or if i'm missing something. for example, right now my watch list where to watch filter only includes various amazon and freevee. i would like to be able to filter by things like hulu, tubi, disney +, etc.  sorry if this is the wrong topic type, it's my first time on the help forums <3