Edit: Appereantly Ubuntu is preferred over Debian for InvoiceNinja. Please switch to this repo https://github.com/jameskimmel/InvoiceNinja-V5-on-Ubuntu
I wrote a basic tutorial for Debian and Ninja v5.
I only tested this behind a reverse proxy and would love to hear some feedback from you.
Also the optional supervisor part is not done yet.
I like this forum but I think github is better suited to open bug reports than here and it is simpler for me to keep it up to date. Link to Github
I am not a native English speaker and will reread my horrible spelling, but not today