Instructions to get the public ip of a lab so you can add firewall rules are at https://learn.microsoft.com/azure/lab-services/how-to-configure-firewall-settings.
If you would like to up vote the 'enable browser-based connection' idea for Azure Lab Services, that feedback idea is at https://feedback.azure.com/d365community/idea/81300afb-7726-ec11-b6e6-000d3a4f032c.
Thanks,
Elizabeth