Chrome does not let you customize the new tab page. The new tab page always opens a custom Google Search page, and Chrome extensions do not work on this page.
This extension lets you point the new tab page to a URL of your choice. It can be Google.com, your company's homepage, or a blank page. It is lightweight on your browser (<50kb - compared to, for example, Grammarly, which is 36MB), has no tracking, and is straightforward to use.
Some popular choices:
1) Google - https://google.com
2) Voice In Notepad - https://dictanote.co/voicein/notepad/
3) Bing - https://www.bing.com
4) ChatGPT - https://chat.openai.com
5) Blank Page - about:blank
You can point the new tab to a local file URL too. A local file URL looks like file:///C:/Documents/test.html on Windows file:///Users/anil/test.html on Mac. To get the local file URL of a file on your system, open the file in a new tab in your browser. Then copy the URL shown in the address bar.
You can set the URL to an internal page like chrome://apps too.
Customization:
1) Focus on the address bar on the new tab page: When checked, the focus and cursor are in the address bar when you open a new tab page. When unchecked, the focus is on the page.
If you want to disable the custom new tab extension, you can do so by going to chrome://extensions and disabling this extension.