Hi all,
Noticed that on the doc it's "https://postiz.example.com/integrations/social/linkedin"
But the actual link sent to LIn is .../integrations/social/linkedin-page
Dunno if it's good but I also add .env:/app/.env in Docker compose "volumes" as I saw a ".env.example" in /app ... 
It works
volumes:
- postiz-config:/config/
- postiz-uploads:/uploads/
- .env:/app/.env
cheers