I got a list of all users of my application in the sandbox at
https://platform.devtest.ringcentral.com/restapi/v1.0/account/~/extension
Now I'm inserting the id into the ExtensionId and getting the "errorCode"
error: "CMN-408",
"message": "In order to call this API endpoint, user needs to have [EditPersonalContacts] permission for requested resource."
How do I grant access rights for this action?