I haven't tried it myself but according to the FAQ:
"Jitsi offers a telephony interface that allows users to dial into a conference or for placing dial-out reminder calls. You can try this for free on meet.jit.si. Self-installed Jitsi Meet deployments will need to setup and configure Jigasi with a SIP provider to connect to the phone network. "
"Jitsi offers a telephony interface that allows users to dial into a conference or for placing dial-out reminder calls. You can try this for free on meet.jit.si. Self-installed Jitsi Meet deployments will need to setup and configure Jigasi with a SIP provider to connect to the phone network. "
https://jitsi.org/user-faq/