CM Registration (CMREG) - Invitation Codes - Assigning Codes to Download Manager's Groups
Assigning Invitation Codes to Download Manager Groups
This option will only be available if both plugins are enabled.
To do this, head to CM Registration Pro → Invitation Codes.
Then, click in the Add invitation code button
In the creation screen, you will see the option "Assign user to CMDM User Group", as highlighted.