I mean, i have even written the explanation

If nginx is installed first, lets stop nginx so certbot can listen to port 80

server {
listen 80;
server_name bin-bash.ch;
return 301 https://$server_name$request_uri;
}

server {
listen 443 ssl;
listen [::]:443 ssl;
server_name bin-bash.ch;

ssl_certificate /etc/letsencrypt/live/bin-bash.ch/fullchain.pem;
ssl_certificate_key /etc/letsencrypt/live/bin-bash.ch/privkey.pem;

# If you don't wanna serve a site, comment this out
root /var/www/html;
index index.html index.htm;

location /_matrix {
  proxy_pass http://127.0.0.1:8008;
  proxy_set_header X-Forwarded-For $remote_addr;
}
location /.well-known/matrix/server {
  return 200 '{"m.server": "matrix.bin-bash.ch:443"}';
  add_header Content-Type application/json;
}
location /.well-known/matrix/client {
  return 200 '{"m.homeserver": {"base_url": "https://bin-bash.ch"},"m.identity_server": {"base_url": "https://vector.im"}}';
  add_header Content-Type application/json;
  add_header "Access-Control-Allow-Origin" *;
}

}