List users who have role assignments at this merchant

Example response

{
  "success": true,
  "data": [
    {
      "id": "123e4567-e89b-12d3-a456-426614174001",
      "email": "user@example.com",
      "first_name": "John",
      "last_name": "Doe",
      "default_partner_id": "123e4567-e89b-12d3-a456-426614174001",
      "default_merchant_id": "123e4567-e89b-12d3-a456-426614174001",
      "created_at": "2024-03-19T12:00:00Z",
      "updated_at": "2024-03-19T12:00:00Z",
      "role_assignments": [
        {
          "id": "123e4567-e89b-12d3-a456-426614174001",
          "role": "global:admin",
          "created_at": "2024-03-19T12:00:00Z"
        }
      ]
    }
  ]
}