fax line

I have a t-mobile number attached to my account for an accessory addition. Can this number be added for the option 4 voicemail "Fax Forwarding Number" that the prompt of number 4 on voice mail requires to be setup.  If so how can this work when there is no actual fax machine at that number.  Nothing is at that number.  Seems like a hopeless dream.  Will have to subscribe to some fax app.  Please reply if you have any insights or found the ability to use this t-mobile fax option without an actual fax machine connected to same.