You can use BGP to connect a VBR to an on-premises IDC. You only need to add BGP peers that communicate with the VBR to the corresponding BGP group, and advertise the BGP network in the VBR, then BGP dynamic routing can be achieved between the on-premises IDC and the VBR.
Note: BGP can only be used to achieve dynamic routing between an on-premises IDC and a VBR. If you need to connect an on-premises IDC to a VPC, you still need to configure a static route for the VBR and the VPC respectively. For more information, see Access a VPC under the same account through a physical connection.
Log on to the Express Connect console.
In the left-side navigation pane, click Physical Connection > Virtual Border Router.
Click the ID of the target VBR.
Click Advertise BGP Network on the page of VBR Details.
Enter the VPC CIDR block or VSwitch CIDR block to be connected with the on-premises IDC, and click OK.