Communication with light crew using USB headsets on computers most likely Chromebooks

Looking for a good way to communicate with 5 light crew members as we don't have headsets and during shows it can be annoying when the spot crew is messing up and we can't tell them that they are screwing up. We've tried many options such as soundtrap using the call collaborators feature but that times out after a certain amount of time. We've also used Zello (on our phones) but we keep notes on our Chromebooks so that wasn't Ideal does anyone have any suggestions sorry if this isn't the right place to post this it was the first thing I could think of.

-Note Any program online will work for us as long as it is open communication not push 2 talk. Hangouts is blocked for our Chromebooks we've tried. This is at a school hence why hangouts is blocked.