Accessing a PiHole Docker Admin Page from the Internet

My Gold Plus (Router Mode) is at 192.168.1.1 that is running PiHole in the Docker container as many of us are doing. The PiHole admin page is at 172.16.0.2.

Let's say my internet address is 340.228.261.112 and I want to use external port 9980 that eventually gets forwarded to 172.16.0.2:80.

I would like to access the PiHole admin page when not connected to my local network?

Basically, I have four Docker PiHole systems I want to access from the PiHole app wherever I am.

I am just stumped how to forward networking in and out of the Docker container.

Suggestions?