Is there anything like i want to add my navbar on every website using my own chrome extension? [closed]

I’m building one chrome extension with Reactjs and it’s work is to show stock details on top of every website and it’s position should be fixed, but I’m facing one issue that is my extension navbar is overlapping website navbar.

I want to add my custom navbar then website own page.

I have used document.body.appendChild() also added position: fixed
But not working.