su password in tryton docker

I’m trying to setup a tryton demo, and I want to define my own modules inside the docker containers I’m using (these =>

I try to create a new directory in the /home directory, in order to define there my own tryton modules, but I do not have enough permission so I execute su. The problem is that I do not know the root password.

Does anyone know which is it? Or, where should I define my tryton modules inside the docker container?

Source: StackOverflow