It would work the exact same way I can call an analog phone line from my phone. At some point, yes, the digital signal from my phone gets converted to an analo

It would work the exact same way I can call an analog phone line from my phone. At some point, yes, the digital signal from my phone gets converted to an analog signal to be sent over traditional telephone wires. My phone just has to produce the right noise for a receiving fax machine to understand it once the noise is converted to an analog signal.