I want to make a primitive browser app when i get channel name in chrome console everything works but in content.js file it return Uncaught TypeError: Cannot read properties of null (reading 'text'). Сonsidering from similar problems, I guess that the DOM may not have time to be loaded before the script will be executed, although I'm not sure if that's the only issue.

my manifest.json

{
    "manifest_version": 3,
    "name": "chan. filter",
    "version": "0.1.0",

    "permissions": [
        "tabs",
        "activeTab"
      ],

    "content_scripts": [
        {
            "matches": ["<all_urls>"],
            "run_at": "document_idle",
           "js": ["content.js"]
        }
    ]
}

here is content.js

document.querySelector("#meta-contents #channel-name a").text;