As far as I know, they are internal to jitsi, and so you do not need to create A records or anything like that.
Thanks for reply, but I try ping to this subdomains all time out ? So this for what ?
If you read the README.md in Jibri’s Github you will find every step you need to install and configure jibri.
Those “mydomain.com” refers to the server in which you installed your jitsi-meet. So, in order to be able to config Jibri, first make sure that you have a FQDN that points to your jitsi-meet server (assuming you have one and configured the SSL part in the jitsi installation), than substitute those “mydomani.com” inside config.json (/etc/jitsi/jibri/config.json) with your jitsi-meet domain.
Correct — that’s to be expected.