Installing Ghost on Mythic Beast Raspberry Pi4 on Ubuntu 20.04

So I have just discovered Mythic Beasts (MB) Pi4 offering for about £15 a month … lift AWS/DO prices out the water. Anyway, so I’m trying to install Ghost here, obviously I’ve run into a million setbacks, probably because of IPV6 and the way the Pi4 is running at MB.

I have finally got Ghost installed and running, but configuring Mailgun (in JSON config and Newsletter API) fails. I’m not sure if this is even going to work, because Mythic Beasts only supports IPV6 (and proxied IPV4) so I’m running IPV4 through their proxy. Not sure if this will affect Mailgun working or not … that’s about as far as my knowledge goes.

Has anybody else set Ghost up self hosted on a Pi with Mailgun that can offer any advice?