I've had some trouble getting a Netgear 341U to install on a Mac. Here's what I've found to work and also what you're looking for.
The proper Netgear 341U setup shows WWAN LTE as an option as a network to connect. When the Netgear 341U is plugged in, the WWAN LTE will show as connected.
I've let the drivers install when you first plug the card in, but this did not work for me. Somehow, they just didn't show the WWAN LTE connection. The solution seems to be go to Sprint's site and download the drivers from there with the card plugged in. Download the drivers. Install the drivers and reboot - all with the card still plugged in.
Drivers located here: