While not related to Yunite, that's an easy concept every Discord admin should now. First, configure Yunite to assign a role to verified members. If you don't know how, please visit
Next, follow the steps in this GIF.
To have the Registration module change nicknames, you need to
Enable this option on the website. You can find it on the Registration Settings page as the second option.
Grant Yunite permissions to Manage Roles. Generally, we suggest that you grant Yunite Administrator permissions to make sure everything runs smoothly.
Move Yunites role above the highest role if those people whose nicknames should be changed. Generally, we suggest that you move Yunites role on the top of the role list to make sure everything runs smoothly.