Nextcloud Spreed.Me + SIP (asterisk) bridge

Guys,

We are using Spreed.Me and it works great.
But sometime we meed the cases when participants does not have internet around or they feel comfortable by just call from usual line or sell hone.

We have Asterisk server in our infrastructure with PSTN.
Are there any way we can connect call from asterisk to conference call going on in NC Spreed.me.

Forgive me if I am asking something stupid. I am not enough familiar with WebRTC.

I’ve read somewhere that spreedme has a SIP feature, so i believe it can be done. How?
That’s the real question.

There was question on github but no much answers about.

Meanwhile you can use X-Lite softphone.

How X-Lite softphone related here?
That is just SIP Client. Nothing more.

My topic about totally different thing.
How to implement SIP dial-in to Nextcloud Spreed.me conference.