{
  "name": "gamification-engine",
  "description": "gamification-engine (gengine) is a framework for developing gamification features for your application",
  "keywords": ["gamification", "python", "postgresql"],
  "website": "https://gamification-software.com/",
  "repository": "https://github.com/ActiDoo/gamification-engine-dokku",
  "logo": "https://www.gamification-software.com/img/300xNxlogo.png.pagespeed.ic.1XGSjEHnoq.webp",
  "success_url": "/admin/",
  "scripts": {
    "postdeploy": "initialize_gengine_db production.ini reset_db=True populate_demo=True"
  },
  "env": {
    "URLCACHE_ACTIVE": {
      "description": "Deactivate URL cache.",
      "value": "False"
    }
  },
  "addons": [
    {
      "plan": "papertrail:choklad"
    },
    {
      "plan": "heroku-postgresql:hobby-dev",
      "options": {
      }
    }
  ],
  "buildpacks": [
    {
      "url": "https://github.com/heroku/heroku-buildpack-multi"
    }
  ]
}

{
  "name": "gamification-engine",
  "description": "gamification-engine (gengine) is a framework for developing gamification features for your application",
  "keywords": ["gamification", "python", "postgresql"],
  "website": "https://gamification-software.com/",
  "repository": "https://github.com/ActiDoo/gamification-engine-dokku",
  "logo": "https://www.gamification-software.com/img/300xNxlogo.png.pagespeed.ic.1XGSjEHnoq.webp",
  "success_url": "/admin/",
  "scripts": {
    "postdeploy": "initialize_gengine_db production.ini reset_db=True populate_demo=True"
  },
  "env": {
    "URLCACHE_ACTIVE": {
      "description": "Deactivate URL cache.",
      "value": "False"
    }
  },
  "addons": [
    {
      "plan": "papertrail:choklad"
    },
    {
      "plan": "heroku-postgresql:hobby-dev",
      "options": {
      }
    }
  ],
  "buildpacks": [
    {
      "url": "https://github.com/heroku/heroku-buildpack-multi"
    }
  ],
  "stack": "cedar-14"
}

Change stack to cedar-14 (for nginx-buildpack)
Change stack to cedar-14 (for nginx-buildpack)