What keystroke do you use to select tty[1234] in d-i in KVM virt-install console?

[David <bouncingcats@gmail.com>]

Hi list readers,

On buster, if I run 'virt-install' with debian-installer with
preseed arguments including
    --graphics none
    --extra-args "auto=true priority=critical console=ttyS0 ..."

to specify a text console KVM install then it all works nicely.

The GUI is LXDE, the terminal emulator is lxterminal.

Here's a screenshot (your viewing is not required, merely optional):
https://imgur.com/a/WGDdniX

We see there, the top line of the text console has text like this:
    (1*installer) 2 shell 3 shell 4- log
to indicate that tty1 is being shown, and that tty2,tty3,tty4 are
available.

tty4 is valuable because it contains log information.

My question is:
    What keystroke do I use to switch between tty1 and tty4?

I tried alt+F4 but that closes the lxterminal process window on the host.
I tried ctrl+alt+F4 but that takes me to tty4 on the host, not in the VM.