manifest.json

{

  "description": "Simple Modify headers ",
  "manifest_version": 2,
  "name": "simple-modify-headers",
  "version": "1.6.3",
  "homepage_url": "https://github.com/didierfred/SimpleModifyHeaders",
  "icons": {
    "48": "icons/modify-48.png"
  },

  "permissions": [
    "activeTab","storage","webRequest", "webRequestBlocking", "<all_urls>" ,"tabs"
  ],
  
  "background": {
    "scripts": ["background.js"]
  },

  "browser_action": {
    "default_icon": "icons/modify-32.png",
    "default_title": "Simple Modify Headers",
    "default_popup": "popup/menu.html"
  },
  
  "applications": {
  "gecko": {
    "id": "{f6ca2dfb-43a6-4334-9fad-8d5a71a1fe67}",
    "strict_min_version": "42.0"
     }
  }
}