Hi @t-shinkai! Welcome to the community. 
Podman/ruNC isn't formally supported as a deployment option in our documentation, but it is OCI compliant and should thus be able to run a Retool instance without any issues.
Because it isn't formally supported, though, the setup process may require additional configuration that is beyond the scope of our documentation and other support offerings. As evidence that it is possible, though, there has been at least one other user that deployed with Podman!
I'm happy to answer any additional questions you may have but will be of limited value if you run into issues. 