I am strying to set httpS on my Strapi production but it is very difficult. I followed the tutorial written by derrickmehaffy, but it does not work for me. :'(

My pm2 service: pm2 configuration

My /etc/nginx/conf.d/upstream.conf file :

# Strapi upstream server
upstream strapi-gatsby {
    server localhost:1337;
}

My /etc/nginx/sites-available/strapi.live-for-good.org.conf file :

server {
# Listen HTTP
    listen 80;
    server_name strapi.live-for-good.org;
# Define LE Location
    location ~ ^/.well-known/acme-challenge/ {
      default_type "text/plain";
      root         /var/www/html;
    }
# Else Redirect to HTTPS // API
#    location / {
#      return 301 https://$host$request_uri;
#    }
}

I cleared the default package in sites-available and sites-enabled, made the link, and when I wanted to check it with service nginx configtest, it fails

But, when I launch sudo nginx -t && sudo service nginx reload, I got this :

nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: configuration file /etc/nginx/nginx.conf test is successful

System

Node.js version: 12.16.1
NPM version: 6.13.4
Strapi version: 3.0.0-beta.19.3
Database: mongoDB on MLab
Operating system: ubuntu 18.04