'browser_action' requires manifest version of 2 or lower

Question

What should I update in my manifest.json file? When I load unpacked there's an error called 'browser_action' requires manifest version of 2 or lower., what should I do to fix it?

{
    "manifest_version": 3,
    "name": "Tab Saver",
    "description": "Save and open tabs automatically",
    "version": "1.0",
    "permissions": [
        "tabs",
        "storage",
        "activeTab"
    ],
    "background": {
        "service_worker": "index.js"
    },
    "browser_action": {
        "default_popup": "popup.html"
    }
}