I am still adding custom trusted root support to the Domino container project.
You will be able to just specify a trusted root to add to the local Linux trust store.
Like other low level functionality this works differently on different Linux flavors.
Here is what I am adding for SUSE, for Debian/Ubuntu and basically all the other Redhat/RPM based systems (I rested Rocky, Alma & Co so far).
This is a companion discussion topic for the original entry at https://blog.nashcom.de/nashcomblog.nsf/dx/how-to-add-a-trusted-root-to-linux.htm