REST Create Sales Persons 1018 error

Hi

I tried new APIs Sales Person Objects.

Marketo REST APIs: Sales Person Objects » Marketo Developers

But "Create Sales Persons" does't work error 1018.

Does anyone know how to enable?

MY REQUEST

999-IBN-999.mktorest.com/rest/v1/salespersons.json?access_token=xxxxxxxxxxxxxxxxx

MY REQUEST BODY

{

   "action":"createOrUpdate",

   "dedupeBy":"dedupeFields",

   "input":[

      {

         "externalSalesPersonId":"whoami@company.com",

         "email":"whoami@company.com",

         "firstName":"Ichiro",

         "lastName":"Suzuki"

      }

   ]

}

RESPONSE

{"requestId":"1ae0#14ebe72d01d","success":false,"errors":[{"code":"1018","message":"SalesPerson API disabled"}]}