If you’re self hosting you can use Dreamhost as your DNS provider, you can use its API to update DNS records with your dynamic IP from command line.
I recently found the DreamDNS updater script which makes it easier, I haven’t configured this to be a script to run automatically on Turris Omnia at reboot, but I was able to test it works from command line from a host with dynamic IP.
If I get to that I’ll eventually document this in the wiki, ideally it would need a new license so its code can be contirbuted to OpenWRT/Turris.