Examine source code of shoplab: Easy Image Picker

{
  "manifest_version": 3,
  "name": "shoplab: Easy Image Picker",
  "version": "0.29.1",
  "description": "Replaces Shopify's theme-editor picker: browse, search and pick organized images. Requires the shoplab: Easy Image Picker app.",
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "easy-image-picker@shoplab.cc",
      "strict_min_version": "128.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": [
          "technicalAndInteraction"
        ]
      }
    }
  },
  "permissions": [
    "storage",
    "scripting"
  ],
  "host_permissions": [
    "https://admin.shopify.com/*",
    "https://online-store-web.shopifyapps.com/*",
    "https://*.myshopify.com/*"
  ],
  "background": {
    "scripts": [
      "api.js",
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "https://admin.shopify.com/*"
      ],
      "js": [
        "content-admin.js"
      ],
      "run_at": "document_start",
      "all_frames": false,
      "world": "MAIN"
    },
    {
      "matches": [
        "https://admin.shopify.com/*"
      ],
      "js": [
        "api.js",
        "config.js",
        "bridge-admin.js"
      ],
      "run_at": "document_start",
      "all_frames": false,
      "world": "ISOLATED"
    },
    {
      "matches": [
        "https://online-store-web.shopifyapps.com/*"
      ],
      "js": [
        "api.js",
        "config.js",
        "content-customizer.js"
      ],
      "run_at": "document_idle",
      "all_frames": true,
      "world": "ISOLATED"
    }
  ],
  "web_accessible_resources": [
    {
      "resources": [
        "icons/*.png"
      ],
      "matches": [
        "https://online-store-web.shopifyapps.com/*"
      ]
    }
  ]
}