Ok, I found this : Publishing linked notes in Joplin Cloud
We booked joplincloud as team at our school.
For example we build a technical documentation for all classrooms, one note for every room and one index to reach the notes. This is quite easy implemented with the back-links-plugin. Our aim is to puplish this for all collegues. But then the links don’t work. 
Please can you look again in this topic and prove the implementation of publishing linked notes.
Sincerly, Helge