GMass: Powerful mail merge for Gmail

{
    "update_url": "https:\/\/clients2.google.com\/service\/update2\/crx",
    "name": "GMass: Powerful mail merge for Gmail",
    "version": "6.0.21",
    "description": "A powerful mass email and mail merge system for Gmail.",
    "short_name": "GMass",
    "icons": {
        "16": "GMass16.png",
        "48": "GMass48.png",
        "128": "GMass128.png"
    },
    "manifest_version": 3,
    "content_scripts": [
        {
            "world": "MAIN",
            "js": [
                "gmassloaderlocal.js"
            ],
            "matches": [
                "http:\/\/mail.google.com\/*",
                "https:\/\/mail.google.com\/*",
                "https:\/\/inbox.google.com\/*",
                "http:\/\/inbox.google.com\/*"
            ],
            "run_at": "document_end"
        },
        {
            "js": [
                "jquery.js",
                "gmass-globals.js",
                "gmass-DEPLOY-MANIFESTV3.js",
                "gmasssdk.js",
                "jquery.bpopup.min.js",
                "select2.full.js",
                "selectize.js",
                "walkthrough\/walkthrough.js"
            ],
            "css": [
                "Gmass.css",
                "select2.css",
                "selectize.css",
                "custom.css"
            ],
            "matches": [
                "http:\/\/mail.google.com\/*",
                "https:\/\/mail.google.com\/*",
                "https:\/\/inbox.google.com\/*",
                "http:\/\/inbox.google.com\/*"
            ],
            "run_at": "document_end"
        }
    ],
    "background": {
        "service_worker": "background_service.js"
    }
}