How Did You Install Qubes?

hi @Insurgo this is to continue the discussion in firmware backdoor ,
about recommended installation for Qubes + Heads laptop.

i remember, i can install Qubes, into Heads laptop, from USB thumbdrive,
without being accompanied by detached pgp signature,
& the installation was success.

so, how to do the recommended installation above ?

does it mean, we need to import QMSK & release signing key, into Heads ?

thanks & best regards,