I installed Linux and FreeBSD to a RPi4 the past few days just writing the image to SD and booting it 
(oS TW and FreeBSD had SSH post-boot)
Vultr VPS with custom ISO installs I think had VNC in their web interface; not sure the specifics, but it seemingly just remote controlled the machine as if I was in front of it (didn’t matter the OS; it displayed GRUB boot, TTY, and installers the same as if bare-metal)