How to enable PIN for SIP dial-in

I have a self-hosted jitsi with jigasi. I need to setup it to enable users calling from SIP phones to enter PIN in order to join correct room.
Is there a detailed guide for this?
I stumbled upon this post, but link in answer is dead.
I’ve also read this topic, and I can’t find any resources on conferenceMapper.

What is conferenceMapper, and how to configure it?
How to make jitsi generate and display pin and phone number in conference?

I understand that it’s all i can do on jitsi side, the rest must be done by setting up IVR to get pin from user, check what room is under given pin number somehow, and add Jitsi-Conference-Room sip header to the call. Is that correct?

This is service you can create yourself. You can find documentation needed for its implementation here: https://github.com/jitsi/jitsi-meet/blob/master/doc/cloud-api.swagger Or you can use the one used on meet.jit.si (check config.js for the exact address).

By configuring dialInNumbersUrl and dialInConfCodeUrl, the first one returns the list of numbers and the second one is the conference mapper, which is responsible for returning the conference name to pin mapping.

Yep, that’s correct.