can't find the original pinned apps in the ubuntu dock [closed]

I've recently reinstalled Ubuntu. I'm using Ubuntu 24-04 LTS.I have some icons in the dock, such as Files, App Center, Help and Shell (it's a FreeDOS computer) and I would like to unpin them but being able to repin them in the future provided that I need them.Those apps don't appear in "Show Apps".

The problem is that if I unpin them, how can I repin them again?

I have searched in /home/$USER/.local/share/applications but none of them are there.

Thanks!