Error of create Tunnel SVT

Hello, I want to create a tunnel for Simple Voice Tchat, but when I put the agent in, it says that it is not supported. I use Crafty Controller and the Playit plugin with Paper 1.21.11. I can join the server from anywhere, but I don’t know why my agent isn’t supported, even though my server is working fine. I need to install the Playit program in my Proxmox virtual machine to create a compatible agent?