Originally they have php blocked to 7.0
I had to open several technical tickets and eventually a claim. Only then they unblocked my php selector and they installed all form me.
So FLARUM isn't in its standard offer, you must impose yourself... may be contacting them as a community they can include FLARUM between their standard packets.
Indeed they are very cheep = basic plain with 1 year free domain + already installed cloudflare https = 1.99 / mo.