Still a bit puzzled here. If I go to the "Phone Numbers" page in the API documentation, and use that same ID, it’ll return the phone number information just fine, so I believe I’m using the proper number. 

This morning I’ve also tried removing the ID all together and leaving the rest as-is, and I get a few different error messages.

This one when I leave “UseAsCommonPhone” blank:
 

{
  "errorCode": "FeatureNotAvailable",
  "message": "Unknown device update use case",
  "errors": b
    {
      "errorCode": "DEV-127",
      "message": "Unknown device update use case"
    }
  ]
}

And this when I set “UseAsCommonPhone” to false (these are users, trying to automate our extension re-assignments during employee onboarding):

{
  "errorCode": "BIL-101",
  "message": "Feature >Hot desk DL] is not available for current service plan",
  "errors": l
    {
      "errorCode": "BIL-101",
      "message": "Feature  Hot desk DL] is not available for current service plan",
      "feature": "Hot desk DL"
    }
  ],
  "feature": "Hot desk DL"
}

Is my whole issue because RingCentral doesn’t want me to create a feature they have on a higher plan? All I’m trying to do is automate our on-boarding so that my team doesn’t mess up assigning call queues, hold music, typos in the email address, etc. 

I believe there is another way I can do it, as my current C# automation works fine but I’m trying to move it to PowerAutomate. But would appreciate it if someone could verify that that’s the case before I re-do it all? 

Thank you! 

In this case, you should submit a dev support ticket where you can provide details the use cases where you want to update a device, and on-boarding a new user programmatically. The dev support team then can assist you better with detailed inputs/requirements.

For the Hot Desk phone, the best way to start is to add a hot desk manually (see the instruction here). Then if it fails because of the account plan limitation, then create a customer support ticket to get help.

Okay that makes sense, thank you as always Phong!