Error when trying to create mock app subscription

I get this error when I try to create a mock subscription through the graphql api playground. I’m working on an automation app:

{
  "error_message": "User unauthorized to perform action",
  "error_code": "UserUnauthorizedException",
  "error_data": {},
  "status_code": 403,
  "account_id": 24876002
}

Here is the mutation I’m trying to execute:

mutation {
  set_mock_app_subscription (
       app_id:123345,
       partial_signing_secret: "r6374e82h",
       is_trial: true,
       plan_id: "basic_plan_15_users"
  ) {
    plan_id
  }
}