Greasy Fork

Open page in the Steam app

Script to open any oficial Steam page (https://steamcommunity.com/ and https://store.steampowered.com/) in the desktop app.

(The "Open In Steam" script found in this site doesn't seem to work, you can update that one if you want).

this one is really old
https://greasyfork.org/en/scripts/10727-open-in-steam

this one is newer and should work
https://greasyfork.org/en/scripts/397563-open-link-in-steam-client