Config file: where is it coming from?

Hello,
when I look at the jitsi-meet code I see that the config.js file (https://github.com/jitsi/jitsi-meet/blob/master/config.js) is imported in the HTML (https://github.com/jitsi/jitsi-meet/blob/master/index.html#L175).

But then, in the code, I print in the variable connectionConfig (https://github.com/jitsi/jitsi-meet/blob/master/connection.js#L97) and I see different values from the ones in the config.js.

Where is this configuration coming from?
Thanks in advance