Obi 200 voice/Fax Configuration Question

I bought the Obi 200 and set it up with a new Google voice telephone number for voice calls. But, I want to also be able to send "and" receive faxes from it- through my Brother multi-function printer/fax etc (MFCL2700DW). Someone said I needed another separate dedicated telephone number for faxes.
So, I created a second Google account and acquired a second free telephone number that way.
1. Can anyone tell me how to set up my Obi200 to be able to send "and" receive faxes with 2 Google Voice numbers?
2. Did I even need to acquire the second Google Voice telephone number? Could I have set up my obi 200 with only one GV telephone number to send and receive faxes? If so, how would I have done that?
Thank you.