I installed a plugin and the site is completely gone.

Warning: 502 Bad Gateway
Plugin: https://github.com/TheWorms/nodebb-plugin-recent-cards-cabane-libre#readme
Site: https://kazancsohbetleri.com/
Server: Ubuntu LEMP, Digitalocean VPS

How can I solve this problem?

Hey.

Nodebb looks great but I have no idea about the Nodebb installation. And I don't speak English very well. All I know is that I want to do it. Where do I start installation?

I have Digitalocean VPS server, a domain and a notebook ^^

Please show me the way, thank you so much...