Does OSE work with Raspbian Lite 64-bit?

I ask because even the Screenly docs https://support.screenly.io/hc/en-us/articles/360042164173-Getting-started-with-Screenly-OSE don’t say.

This is on RPi3B+
I tried with 64-bit but after running the Curl command and reboot no Screenly.
I’m trying again with 32-bit but that looks like it may have stalled during the optional (wish I hadn’t selected it!) system update/upgrade whatever it calls itself.
Tried it again and still nothing.

Basically, any install on top of Raspbian doesn’t work as advertised.