CTAP Proxy Clarity

I’ve been following this guide(CTAP proxy — Qubes OS Documentation) and I need some clarity

sudo apt install qubes-ctap

I know you should install this on the templates you’ll be logging in from, but does this also apply to sys-usb’s template? If I’m using sys-usb by default, do I need to install this on default-dvm(sys-usb’s default template)?

Whenever I try to run this command to install qubes-ctap on default-dvm’s template(not the app) it disappears on restart (I check with: apt list --installed | grep qubes-ctap). If I don’t even need to install qubes-ctap on default-dvm then this shouldn’t be a concern

Are we talking of the template of default-dvm (which is a disposable template)? Something like fedora-43-xfce?

Yeah, my default-dvm’s template is debian-13-xfce