@shal, thank you for your reply!
looking at the link you provided it looks like the port we need to use is 443 as we use Websockets
MQTT over WebSockets: 443 (SSL)
Port 443 is the one we are using already to connect to your platform, however, there's no mention of where or how to add our TLS certifications to the broker, or where to download the server certification to be used at the client-side.
Once again, Thank you for your support!