This was set up in case Readysell needed it moving forward, so far it is not required or needed, please disregard this at this point in time.
Navigation panel > Administration > Advanced > System Types
Name: CUSTOM-FIELD-GROUP
On the right hand side, under References
The first row has a filter on it, therefore it is a search field not an entry field to add new custom field groups.
Click on button New
Add in the Code for the new custom field group
Add in the Description for the new custom field group
Leave the value field empty