You created a new ExpressRoute circuit with your service provider and now must provision it. What piece of information must you give to the service provider so they can complete provisioning?

When provisioning an ExpressRoute circuit, the service key (also known as the circuit ID) is a unique identifier generated by Azure. You must provide this key to your ExpressRoute service provider so they can complete the provisioning process on their end, linking their network to your Azure ExpressRoute circuit. The IKEv2 shared key is used for VPN tunnels, not ExpressRoute. A certificate is not directly used for ExpressRoute circuit provisioning. While public IP addresses are involved in network configurations, the specific public IP address of your Azure resources or the ExpressRoute gateway is not the piece of information required by the service provider to provision the circuit itself.