Can't Use Extension numbers with make.com for SMS

I am trying to setup an automation using make.com (integromat) between Monday.com and RingCentral. It worked fine with Zapier, but with Make.com I can't select the users phone numbers to send SMS messages. Only the super admin, primary user and fax number, but none of the user numbers. I get the following error:

RuntimeError

Error 403 MSG-304 Phone number doesn't belong to extension

The make.com support say it is an Admin permissions issue at RingCentral.

Any ideas?