Examine source code of Send2Mealie

{
  "manifest_version": 2,
  "name": "Send2Mealie",
  "version": "1.6.1",
  "description": "Adds a configurable 'Send to Mealie' button to supported recipe pages.",
  "browser_specific_settings": {
    "gecko": {
      "id": "send2mealie@firefox",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "browser_action": {
    "default_title": "Send to Mealie",
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon_16.png",
      "48": "icons/icon_48.png",
      "128": "icons/icon_128.png"
    }
  },
  "icons": {
    "16": "icons/icon_16.png",
    "48": "icons/icon_48.png",
    "128": "icons/icon_128.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "permissions": [
    "storage",
    "activeTab",
    "tabs",
    "notifications",
    "https://*.allrecipes.com/*",
    "https://*.bbcgoodfood.com/*",
    "https://*.budgetbytes.com/*",
    "https://*.cooking.nytimes.com/*",
    "https://*.eatingwell.com/*",
    "https://*.food.com/*",
    "https://*.foodnetwork.com/*",
    "https://*.sallysbakingaddiction.com/*",
    "https://*.seriouseats.com/*",
    "https://*.simplyrecipes.com/*",
    "https://*.skinnytaste.com/*",
    "https://*.tasty.co/*",
    "https://*.tastykitchen.com/*",
    "https://*.thepioneerwoman.com/*",
    "https://*.thespruceeats.com/*"
  ],
  "optional_permissions": [
    "https://*/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://*.allrecipes.com/*",
        "https://*.bbcgoodfood.com/*",
        "https://*.budgetbytes.com/*",
        "https://*.cooking.nytimes.com/*",
        "https://*.eatingwell.com/*",
        "https://*.food.com/*",
        "https://*.foodnetwork.com/*",
        "https://*.sallysbakingaddiction.com/*",
        "https://*.seriouseats.com/*",
        "https://*.simplyrecipes.com/*",
        "https://*.skinnytaste.com/*",
        "https://*.tasty.co/*",
        "https://*.tastykitchen.com/*",
        "https://*.thepioneerwoman.com/*",
        "https://*.thespruceeats.com/*"
      ],
      "js": [
        "contentScript.js"
      ],
      "run_at": "document_end"
    }
  ]
}