The touch tones in firertc dont work and numbers that require a selection by pressing a number are useless. I found this page and I pull it up on my smart phone and just play the tone into the laptop 🎤 . It will trigger the menu selection and make it ring through.
I went low tech and just used a second cell phone, placed it's speaker against the mic of my firertc phone and hit the numbers. Sometimes it takes a few tries, but it's always worked for me.
I've gotten it to work by pressing the numbers a bunch of times.