How to add a extension to guacamole?

Hi, same here.
I am currently trying to set up SAML and TOTP.
I have found the folders in the Docker container under “/root/.guacamole/”.
These are linked to “/var/lib/docker/overlay2/{cyptevalue}/diff/root/.guacamole”.
As soon as you make the changes in this directory and then restart Guacamole, the files are overwritten.
So this is not very helpful, but it is a certain approach.
So there must be a folder structure somewhere in UCS where the original files are stored. These would then have to be adapted in order to activate TOPT or SAML.

But here I am also stuck.
It would be nice if someone here could help.