Game pass error

So I’ve been trying to install the game on my external disk, I changed the options on windows like a post here said but I still can’t install on the xbox app, so I found another post that says I need to change the settings of the app and I did but every time I try to install the game only shows disk C and changes the settings on the app to only install on disk C again.

What can I do to change the settings to install the game?