zshesveli is right...
You dont need to do anything...
you just need to put the Master ip or the name of the master.
Are you provisionning yourself?
Did you enter the ip of the master that they gave you?
I mean it can happen 2 things
1-On the company your GF works they have not open port udp 4500 so it wont be able to connect(if they got other people on this system already i doubt this is the case)
2-If they didnt open the port udp 69(which is TFTP port(on the company not you) then he wont be able to upgrade the firmware and if he is not able to upgrade it he wont connect if the fimrware is not the same)
They need to forward those 2 ports to the controller
Now if you enter the master ip address or your girlfrined can you tell us what did appear on the rap 5 console? did it says it was able to see the master? or what happens?
Did the company preprovision it? or you did it yourself?
I bealive your problem is the second one.