How to create a network bridge between wlan0 and eth1 to connect a second eth0 device?

I have a network topology as described in the Network Setup image above. I have a WiFi router on a private 10.12.12.1 network. An Ubuntu 20.04 box, on a Nvidia Jetson, is connected to a WiFi network with an IP address 10.12.12.z. The Nvidia Jetson has two physical eth0 and eth1 devices/cards. I would like to connect a Debian Box that has a physical eth0 interface to the eth1 interface on the Nvidia Jetson. I am unclear on the networking terminology that is needed to achieve this Network Setup but I have started by bridging wlan0 and eth1 on the Ubuntu 20.04 using a netplan configuration as fol

Question by Wess on Super User, licensed CC BY-SA. We show a short excerpt and link to the original thread as credit.