To add on to what @ijeff said, eventually the plan is to open up community contributions. However, they are not needed since so far hosting costs are looking to be around $40/mo (for a setup which is highly available!) which is low enough I’m happy to fund it for eternity.
I’ve seen other instances have luck with asking for low amounts of contributions through ko.fi or GitHub sponsors and we will eventually do something similar. I’m waiting until I have the infrastructure in a stable place (i.e. not changing too much) and I have open-sourced all of the setup work.