Open the Chrome Extensions page by typing `chrome://extensions/` in the address bar
Turn on Developer mode
Click Load unpacked to add a new extension folder
If you mean adding a new item inside an extension’s popup, edit the extension’s HTML file
Add a new `
`, `
`, or `
` element in the relevant HTML file
Update the CSS if needed to keep the layout aligned
Update the JavaScript if the new row needs dynamic content or behavior
Save the files
Refresh the extension on the Chrome Extensions page
Reopen the extension to see the new row