Viber has no sound on my PC

I set up Viber on the PC so my daughter-in-law can make calls since she doesn't own a smartphone. Everything seems fine, except I can't hear anyone when I call them from my phone. I can hear the other person perfectly through the computer speakers, but they can't hear me. Help. I'm running Windows 10 and using these standard speakers

Maybe take a quick peek at your speaker settings—you know, down by the clock in the taskbar—just to make sure the output is actually set to your speakers. On my rig, it’s set to Realtek High Definition Audio..