You will have to make sure that the Additions folder contains the nametags.yml file. If it doesn't, create it. Make sure that the following is in the file. You can modify it if you want.
Now you can add your own group and set the order of it. The order is determinative if a player is assigned to more than one nametag group. The tag with the lowest order will then be set as their nametag.
To assign players to a group, they need the permission: additions.nametag.GROUPNAME where GROUPNAME is the name of the group as specified in the configuration.
Now you will have to set the actual tag of the nametag group. This could be either
animated or static.
If you want it to be static, just use tag: '&eMVP &6%player%'.
If you want it to be animated, you will have to make it a list (see example below) and add the option updateInterval to the group. This is the time for the animation to go to the next string in ticks. 1 second = 20 ticks.