TL;DR: I got it working with a Raspberry Pi 4 and the Legacy Buster OS.
Now for the story: I followed the instructions to connect the screen to the board to the RPi. I installed the Official Raspberry Pi Imager and used the "Recommended" Raspberry Pi OS (Debian Bullseye port) (32 Bit), released 2021-10-30. When I plugged it in, there was some lights on the RPi flashing, but the it wasn't getting enough power to work. I unplugged the USB from the monitor and used an official RPi USB-C plug to power the RPi and everything turned on (with a white screen, see the last paragraph) and the RPi would react to touches, but any tap would just click on the lower-right corner of the screen (Plugging in a mouse and wiggling it made the cursor show up again). I installed the Raspberry Pi OS (Legacy) (Debian Buster), released 2021-12-02 and the screen worked perfectly and reacted to touches right after installation. I can even work the initial "Raspberry Pi setup" screen!
Also, I couldn't get the screen to work at all (No image, to touch, nothing) when I tried to use a RPi 1 with the Bullseye OS. I could get HDMI output from it and could power the RPi 1 from the monitor, but nothing showed up on the screen. I didn't pursue it any further because it seemed to be steps in the wrong direction for me (this was before I tried switching the OS).
One last thing: with the Bullseye OS, the display looked like it was suffering from a power surge (the display turned white in a way that did not look healthy) when the RPi 4 first booted, but the effect went away and the screen displayed the desktop. With the Legacy OS, this problem went away and it behaves like a normal tablet screen.
I'm sorry for the long post, but I didn't want to skip anything important!