Hi Claude_Schlesser,
I have another website so as an experiment installed Oneall, and it works fine straight out of the box.
I installed the plugin and followed the instructions and I struggled , Facebook have changed their setup so it took a bit o…
OK done that , now get message - App Not Set Up: This app is still in development mode, and you don't have access to it. Switch to a registered test user or ask an app admin for permissions. ?
App is in 'live' mode