is it possible to use this mod (fabric version) on shockbyte, (their tutorials are old), wondering as I'm trying to help someone set it up

https://shockbyte.com/billing/knowledgebase/269/How-to-Setup-Simple-Voice-Chat-on-your-Minecraft-Server.html

At the time of writing, Fabric is not working properly, so we recommend using forge instead.

Ask their support for a solution, but it seems the fabric version isn't working on their servers.