Buster generate does not work on ubuntu

[pokyah]

Hi !

I've ghost installed locally on ubuntu 16.04 under var/www.

http://localhost:2368/ghost/ works perfectly. I can add new posts, etc.. However while running buster generate in the console from the var/www directory I got the following error :

Connecting to 127.0.0.1:2368... failed: Connection refused.

I'm totally new to linux, servers, node.js...

Is it something about permissions ? Should I change something with chmod/chown ?

Thanks for your help