professional wants to return my call / call me back

To have anyone call you back, you have these options:

use your own cell number get a free phone number from any of these services:

You can get free numbers for making outbound calls and texts from these sources and you can use these same numbers to have someone call you back:

Voice.google.com

Talkatone

Call2Friends

Ievaphone

PopTox

TextNow

(note: I have not tested these websites or services other than google voice which many of us use)