Please look around. This has been discussed to death for years: https://itch.io/t/160014/can-i-use-exclusion-filters
Viewing post in Exclude tags option for god's sake
You mean the way you can add something to the URL to exclude a single tag... you know when it works?
Yeah what a spoiled brat I am for wanting one that's easy to use, works consistently and can exclude more than one tag. Clearly this is an insurmountable challenge of UI that is far too difficult to add. Ignore how someone made their own site that does just that
…In that case, perhaps you should be more specific. There is, in fact, a more capable solution made by redonihunter here. Hope this helps: https://redonihunter.itch.io/itch-browse-tag-exclude