Download the latest build from Modrinth or CI and place it into the server's plugins folder. Start the server using paper-1.21.4-232. Modify the configuration file storage.conf, change primary-storage ...
For anyone who gets ERROR 1064 when using authserver.exe or worldserver.exe to populate the necessary databases (acore_auth, acore_characters, & acore_world), check your MySQL version. For whatever ...