Currently, Wappler offers no way to get into a shell inside the Docker container executing the web server. This is a Development target using Docker
Yes that is what the “web server” terminal option is for 
There you have a new bug then, it drops into my Mac’s shell
From the dropdown “terminal” is for local terminal, but the “web server” option is for shell in the docker web server.
So make sure you choose the right one - web server
Oh, I’m not sure what went through my head. Solved!