portainer installation und stack konfigurieren

[Max007]

services:
  app:
    image: 'jc21/nginx-proxy-manager:latest'
    restart: unless-stopped
    ports:
      # These ports are in format <host-port>:<container-port>
      - '80:80' # Public HTTP Port
      - '443:443' # Public HTTPS Port
      - '81:81' # Admin Web Port
      # Add any other Stream port you want to expose
      # - '21:21' # FTP


    environment:
      # Uncomment this if you want to change the location of
      # the SQLite DB file within the container
      # DB_SQLITE_FILE: "/data/database.sqlite"


      # Uncomment this if IPv6 is not enabled on your host
      # DISABLE_IPV6: 'true'


    volumes:
      - ./data:/data
      - ./letsencrypt:/etc/letsencrypt

Wo durch kommt dieser Fehler:
Failed to interpolate config for stack npm. Error: compose config operation failed: failed to load the compose file: validating /data/compose/8/v1/docker-compose.yml: services.app.environment must be a mapping