List of error codes returned from the API services:
| 0 | Server error. Unexpected error from server |
| 1 | Not found. Returned when an attempt was made to reference an ID that does not exist |
| 2 | Property required |
| 3 | Invalid property value |
| 4 | Duplicate index value |
| 5 | Not allowed, insufficient permissions |
| 6 | No payment card registered |