Authorizer is open-source, self-hosted and can be deployed on Railway very easily. octauthent is a freemium service.
I’ve tried Authorizer, and it works with Publii. The developer of the project is very friendly and responsive on Discord.
It helped me to protect my personal decentralized website, thank you very much!
Now with your solution I am more protected!
Web Monetization: It can be implemented on static sites, and there are some interesting demos on gated content: https://webmonetization.org/docs/exclusive-content. That said, it’s not super well known yet, and the only provider at the moment, Coil, just got discontinued. That said, the Interledger Foundation is continuing work on this web standard: https://interledger.org/