I've managed to pin both Twitter and Facebook PWAs to the dock, but when I open the Youtube web app using the 'Youtube' app via the chrome url bar ("to open this link, choose an app" - indicating it has been installed already), and it shows up in the dock, there's no 'pin' option on the menu (there is in the Twitter and Facebook icons).
Also, when I try to launch Twitter or Facebook using the 'super' key (Windows?), they show up in the list of apps right after a couple of relevent keystrokes, but not so for Youtube.
Any ideas?
Ubuntu 23.04