JWT avatar and nick

I have a question. In which section of the code is the avatar and username instantiated in the pre-join page?

I have modified this file : util.lib.lua
because I want to change the structure of the accepted JWT.

The modified section was this :

-- Binds the user details to the session if available

if claims["context"] ~= nil then
if claims["context"]["user"] ~= nil then
session.jitsi_meet_context_user = claims["context"]["user"];

But apparently it does not execute that section of code