Ring central app - Messages

Do you want to receive copies?  or do you want all text messages to go to admin and not to go to any of your users at all?

Either or , both both options on the table , as currently without having Ring cental phone app installed for each and every number , we are not receiving the txt messages ,
Lets me try and explain the scenario.
Currently we have 4 phone lines , 1 phone number is connected with Ringcentral phone app is installed on our technician cell phone , ( no way we can add more lines to the app ) 
we would like all 4 phone number lines to be able received txt massages on that 1 cell device , 
I hope i didn't confused you 
Thank you in advance