Nginx Reversed Proxy for Django

Question

I have my Django Server running on a virtual maschine. I got my own domain and want to access the server just with the domain via Nginx. I got to files in the sites-enabled folder. The problem is that if I try to connect to the Server I get a 403 forbidden message. But if I change the servername from the Reversed Proxy to my static ip I can access the server. Does anybody know what the mistake is, that I can access the Djangoserver just with my domain?

server{
        server_name www.mmjtech.de;
        root /var/www/html;

        location / {
                index index.html index.htm index.html inde.php;
                try_files $uri $uri/ = 404;
        }

        listen 80;
        listen [::]:80;
}


And the following is the second file.


server {
    listen 80;
    server_name mmjtech.de;
    location / {
        proxy_pass http://127.0.0.1:8000;
        proxy_set_header Host $host;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_redirect http://127.0.0.1:8000 http://mmjtech.de;
    }
   # location /static/ {
   #     root /home/myuser/myproject;
   # }
}