Problem description
CAMARA APIs may not support all phone numbers for specific functions in any point in time

Possible evolution
Add a 501 status response with the following message "Service not supported for this phone number"

NotSupported:
   description: Not Supported
   content:
    application/json:
     schema:
      $ref: "#/components/schemas/ErrorInfo"
     example:
      status: 501
      code: NOT_SUPPORTED
      message: Service not supported for this phone number

Alternative solution
N.A

Additional context

• CAMARA APIs may support mobile lines first and then landlines later, vice versa.
• A MNO may support the CAMARA API method, but the MVNO (of the same MNO) does not support it.