It's a beta version! I can't guarantee that updating the world to the beta or exiting the beta will be 100% safe. Make a backup!
Version 1.21.3 was added（1.21.3 should theoretically be supported）
Developer information
Projects on Modrinth are automatically available through a Maven repository for use with JVM build tools such as Gradle.
maven { name = "Modrinth"; url = "https://api.modrinth.com/maven" }
