Google chrome extension add button under the youtube video

Question

I am working on my google chrome extension and i need to know how to add the button under the youtube video. Here is my code

chrome.tabs.onUpdated.addListener((tabId, changeInfo) => {
    if (changeInfo.status === 'complete') {
        chrome.tabs.get(tabId, function(tab) {
            if (tab.url.includes('https://www.youtube.com/watch')) {
                chrome.scripting.executeScript({
                    target: { tabId: tabId },
                    function: () => {
                        // Function to create and inject button
                        function addButton() {
                            const button = document.createElement('button');
                            button.textContent = 'Click Me!';
                            button.style.backgroundColor = '#ff0000';
                            button.style.color = '#ffffff';
                            button.style.padding = '10px';
                            button.style.border = 'none';
                            button.style.cursor = 'pointer';
                            button.addEventListener('click', function () {
                                alert('You pressed the button!');
                            });
                            return button;
                        }

                        // Function to inject button if it doesn't exist
                        function injectButton() {
                            const videoContainer = document.querySelector('#info');
                            const existingButton = document.querySelector('#info button');
                            if (videoContainer && !existingButton) {
                                videoContainer.append(addButton());
                            }
                        }

                        // Start observing
                        const targetNode = document.querySelector('body');
                        const observerOptions = {
                            childList: true,
                            attributes: true,
                            subtree: true
                        };

                        const observer = new MutationObserver(injectButton);
                        observer.observe(targetNode, observerOptions);

                        // Inject button initially if possible
                        injectButton();
                    }
                });
            }
        });
    }
});
console.log("working")

It is background.js file

here is my manifest.json

{
    "manifest_version": 3,
    "name": "YouTube Button Extension",
    "version": "1.0",
    "permissions": ["scripting", "webNavigation"],
    "host_permissions": ["https://www.youtube.com/*"],
    "background": {
        "service_worker": "background.js"
    }
}

My background.js file working, but the button is not showing. There is no errors. I tried to ask ChatGPT but he didn't give me a good answer. Help, please