My VOIP phone no longer works and I’m told that I need to change disable the SIP-ALG. I can’t do that if I can’t access my router. The 192.168.50.1 address does not work.
Sounds like your default IP address has been changed. Connect a device directly to your router then check your devices network properties and find the gateway IP address - that’s the IP of your Pepwave.
Or if you haven’t done so already, register with https://incontrol.peplink.com and add your device there using its serial number then use remote web admin to access it.