How to properly configure https for django on Nginx Proxy Manager?

Question

Django

Hello everyone, tell me why django does not see https? I have an ssl certificate, everything is set up, and on the site itself everything works on https, but when you receive request.get_scheme in the template, the result is http and requests also go with http, what can it be?
Everything is configured using NGINX Proxy Manager - docker-compose:

version: "3"
services:
  app:
    image: 'jc21/nginx-proxy-manager:latest'
    networks:
      testnet:
        ipv4_address: 172.26.0.254
    restart: always
    ports:
      # Public HTTP Port:
      - '80:80'
      # Public HTTPS Port:
      - '443:443'
      # Admin Web Port:
      - '81:81'
    environment:
      # These are the settings to access your db
      DB_MYSQL_HOST: "172.26.0.253"
      DB_MYSQL_PORT: 3306
      DB_MYSQL_USER: "user"
      DB_MYSQL_PASSWORD: "pwd"
      DB_MYSQL_NAME: "npm"
    volumes:
      - ./data/nginx-proxy-manager:/data
      - ./letsencrypt:/etc/letsencrypt
    depends_on:
      - db
  db:
    image: yobasystems/alpine-mariadb:latest
    restart: always
    networks:
      testnet:
        ipv4_address: 172.26.0.253
    environment:
      MYSQL_ROOT_PASSWORD: "pwd"
      MYSQL_DATABASE: "npm"
      MYSQL_USER: "user"
      MYSQL_PASSWORD: "pwd"
    volumes:
      - ./data/mariadb:/var/lib/mysql
networks:
  testnet:
    external: true

nginx settings on the site itself:

server {
    listen 80 default_server;
 
    server_name testss.top;
 
    location /static/ {
        root /var/www/testss;
    }
 
    location /media/ {
        root /var/www/testss;
    }
 
    location / {
        add_header X-Cache-Status $upstream_cache_status;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_set_header Host $http_host;
 
        proxy_redirect off;
        proxy_pass http://backend:8008;
    }
}

Docker-compose site:

version: '3'

services:

  backend:
    build: ./
    container_name: testss_container
    restart: always
    command: ./commands/start_server.sh
    networks:
      testnet:
        ipv4_address: 172.26.0.2
    volumes:
      - ./src:/srv/project/src
      - ./commands:/srv/project/commands
      - static_content:/var/www/testss
    env_file:
      - .env
    depends_on:
      - postgres

  postgres:
    image: postgres:12
    volumes:
      - pg_data:/var/lib/postgresql/data
    env_file:
      - .env
    networks:
      testnet:
        ipv4_address: 172.26.0.4
#    environment:
#      - DJANGO_SETTINGS_MODULE=testss.settings.${MODE}
  
  nginx:
    image: nginx:1.19
    volumes:
      - ./nginx:/etc/nginx/conf.d
      - static_content:/var/www/testss
    networks:
      testnet:
        ipv4_address: 172.26.0.5
    env_file:
      - .env
    depends_on:
      - backend  

networks:
  testnet:
    external: true

volumes:
  pg_data: {}
  static_content: {}

Answer 1

Where is the certificate? Nginx is configured for http judging by the given config.
Or is this Nginx located behind a proxy? If so, then check if the X-Forwarded-Proto header is transmitted from it