https://free-for.dev 검색하니 2가지 나오네요.

  1. https://domcloud.co – Linux hosting service that also provides CI/CD with GitHub, SSH and MariaDB/Postgres database. Free version has 1 GB storage and 1 GB network/month limit and limited to a free domain.
  2. https://filess.io - filess.io is a platform where you can create 1 database of the following DBMS for free: MySQL, MariaDB, MongoDB, PostgreSQL.

planetscale으로 해보려니 좀 귀찮아서 firebase로 구현했습니다.
감사합니다.

도움이 되실지는 모르겠지만 아래 gist 한번 참고해보세요!
https://gist.github.com/bmaupin/0ce79806467804fdbbf8761970511b8c

감사합니다.
firebase로 구현하니 간단하네요. ^^;