Decrypting SSL/TLS Traffic with polarproxy

I’m trying to collect some decrypted web traffic in a pcap file and to do so I chose to use polarproxy since it is able to save the decrypted traffic to a pcap file.

I have a selenium/firefox container set up to eliminate background noise form my host machine.
But i can’t figure out how to connect the containers with one another so that the proxy container gets the traffic from the selenium container.

From my understanding the way to connect containers is --net=container:“name” but I also need to forward the https and trust the root ca according to this:

As you have probably guessed by now I’m neither an expert in networking nor Docker so I am thankful for every recommendation.