Lichess and making free software

I stumbled on this post by the creator of Lichess this morning.

It talks about how Lichess is free and always will be. No ads, no trackers, no paid features. And I love it.

I would love to do something similar to that with Bear Blog, and we have some decent user numbers (nothing near Lichess yet though). I just don't have any experience doing donation based fundraising, or sponsorware software development.

What are your thoughts on this method of monetisation? How would one get started doing that?