Examine source code of myfpl

{
  "manifest_version": 2,
  "name": "myfpl",
  "version": "2.0.3",
  "description": "A browser extension for fantasy.premierleague.com - plan for future gameweeks and update points & league standings in real time.",
  "icons": {
    "16": "favicon16.png",
    "32": "favicon32.png",
    "48": "favicon48.png",
    "128": "favicon128.png"
  },
  "browser_action": {
    "default_popup": "index.html",
    "default_icon": {
      "16": "favicon16.png",
      "32": "favicon32.png",
      "48": "favicon48.png"
    },
    "default_title": "myfpl"
  },
  "content_security_policy": "script-src 'self' 'sha256-oFaBWLRrGx/jiCDQSrRAZHBbl5DYPayZrsG3A4RbcrY='; object-src 'self'",
  "background": {
    "scripts": [
      "/static/js/backgroundMainJs.chunk.js",
      "/static/js/runtime-backgroundMainJs.js"
    ],
    "persistent": false
  },
  "content_scripts": [
    {
      "matches": [
        "https://fantasy.premierleague.com/entry/*"
      ],
      "css": [
        "/contentAuth.css",
        "/contentCore.css",
        "/contentPlayerStyling.css",
        "/contentUpcomingAndPastGames.css",
        "/contentPoints.css"
      ],
      "js": [
        "/static/js/contentPointsJs.chunk.js",
        "/static/js/runtime-contentPointsJs.js",
        "/static/js/0.chunk.js",
        "/static/js/1.chunk.js"
      ],
      "run_at": "document_idle"
    },
    {
      "matches": [
        "https://fantasy.premierleague.com/my-team"
      ],
      "css": [
        "/contentAuth.css",
        "/contentCore.css",
        "/contentPlayerStyling.css",
        "/contentUpcomingAndPastGames.css",
        "/contentMyTeam.css"
      ],
      "js": [
        "/static/js/contentMyTeamJs.chunk.js",
        "/static/js/runtime-contentMyTeamJs.js",
        "/static/js/0.chunk.js",
        "/static/js/1.chunk.js"
      ],
      "run_at": "document_idle"
    },
    {
      "matches": [
        "https://fantasy.premierleague.com/transfers"
      ],
      "css": [
        "/contentAuth.css",
        "/contentCore.css",
        "/contentPlayerStyling.css",
        "/contentUpcomingAndPastGames.css",
        "/contentTransfers.css"
      ],
      "js": [
        "/static/js/contentTransfersJs.chunk.js",
        "/static/js/runtime-contentTransfersJs.js",
        "/static/js/0.chunk.js",
        "/static/js/1.chunk.js"
      ],
      "run_at": "document_idle"
    },
    {
      "matches": [
        "https://fantasy.premierleague.com/leagues/*"
      ],
      "css": [
        "/contentTable.css",
        "/contentAuth.css"
      ],
      "js": [
        "/static/js/contentTableJs.chunk.js",
        "/static/js/runtime-contentTableJs.js",
        "/static/js/0.chunk.js",
        "/static/js/1.chunk.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "permissions": [
    "https://fantasy.premierleague.com/*",
    "webNavigation",
    "storage",
    "unlimitedStorage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{f8d1a7dc-97b4-4346-80e3-d2e0b578bfbe}"
    }
  }
}