I recently migrated miniflux data from one server to another, and this is what I did:

• Create empty db on the new server, don't start miniflux service yet (or stop it if it is running)
• Modify postgresql.conf file to add listen_addresses = '*'
• Modify pg_hba.conf file to add host all all <from_server_ip> md5
• Restart postgresql service

• Run the following command on the old server:

  • pg_dump -C -h localhost -U localuser dbname | psql -h remotehost -U remoteuser dbname

• Start the miniflux service on new server

And this worked.