Amazon web services: Add physical connections to Cisco CSR 1000 on AWS

I deployed 2 Cisco CSR 1000 routers in one VPC-1 in one region A, and in region B I implemented another one.
I would like to make a physical connection between these 3 routers.
Also, I tried to ping between these routers and it was a success that I do not understand because there are no physical connections between them.

For interfaces, only one interface. GigabitEthernet1 with the address of each router, and there's also VirtualPortGroup0 Interface.

IP Interface-Address OK? Method method method
GigabitEthernet1 172.31.34.123 YES DHCP above
VirtualPortGroup0 192.168.35.101 YES NVRAM up