Debian 10.7.0 netinst install in CentOS 8.1 VM – no root or sudo access

I have a CentOS Stream 8.1 system with gnome-boxes (QEMU KVM) and installed a Debian Buster (10.7.0) VM using debian-10.7.0-amd64-netinst.iso. During the install I was prompted to create a user, but was not prompted to set a root password.

After finishing the install, I can boot the VM just fine and login, but I find that the user that was created is not in sudoers, and I cannot su or login as root as I have no password. Google searching tells me root is disabled by default and has no password.

So then I tried adding init=/usr/bin/bash to bootparams, but that causes the boot to hang with what looks like an uninitialized screen buffer on the screen.

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Booting with rw init=/usr/bin/bash (removed quiet) results in the same hang with this:

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How can I set a root password or edit sudoers to add my user?