GobiNet, GobiSerial + AT commands - how to provide user,pass

I am using Sierra’s GobiNet, GobiSerial on Linux kernel 4.4 for the EM7455 device.
To define APN settings and connect the data interface, I’m using AT+CGDCONT and then AT!SCACT to activate the PDP context.
I then obtain a DHCP address with dhclient on the first RMNET interface.

This process works fine, but it’s not clear to me how to define the PDP context for networks requiring a username and password?
AT+CGDCONT doesn’t support that, and I couldn’t find any other AT command that does. Is there a different way to authenticate?


Use the below.