Before you can fully enjoy this mod you will first need to aquire a character creation extender and there are many to choose from but for convienience I have listed a couple here below.

Kawa's Xbawks Character Extender
Its a good choice, simple and room for many races.
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=729426722

Xordaii's Character Creation Extender 100
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=823008631

PLEASE NOTE: A character extender is not required to use Whobound wardrobe features. It is only required if you're intending to play inside the TARDIS as a Gallifreyan (or any other species) in the mod.