Nextcloud Talk bandwidth costs on Azure server

I am trying to push that our non-profit agency use Nextcloud, for inter-agencies team cooperation (25 members), but my management expressed concern about bandwidth costs if we are using Nextcloud Talk over our Azure server, but I understood that Talk is using P2P connection.
Can you please, explain what bandwidth traffic we can expect if our team is using Talk on Azure server?
For example: all video and audio call are going trough server, and you will be charged for every minute of it, or as I already mentioned (but I am not sure) Talk is using P2P connection and there will be no charges for audio and video calls.