RocketChat login with UNA fails

Description

I am using RocketChat as a plugin within UNA from una.io
Everything is setup/installed correctly and the server works. I can get to RocketChat admin.
The problem is, my members get this error trying to login thru my website THE REDIRECT URI PROVIDED IS MISSING OR DOES NOT MATCH
What is wrong?

Server Setup Information

  • Version of Rocket.Chat Server: 3.3.0
  • Operating System: Linux / Centos 7
  • Deployment Method:
  • Number of Running Instances: 1
  • DB Replicaset Oplog:
  • NodeJS Version: v12.14.0
  • MongoDB Version: 4.0.19
  • Proxy:
  • Firewalls involved: CSF

Any additional Information