lost my chrome browser on my laptop

Google no longer offers versions of Chrome that will run on Catalina. If you have deleted all of your copies of that browser, including backup copies, you will not be able to reinstall it.

I believe that Firefox is the only major browser whose current version still supports Catalina. It might also be possible to download an old version of the Chromium-based Brave browser (I haven’t checked).

The Chrome browser is not an Apple product. When you say you “cannot reinstall” it what exactly do you mean by that statement.

It is highly unlikely that the Google Chrome browser just suddenly disappeared. Do you mean it disappeared From the Dock at the bottom of your screen?

Hold down the ⌘ Command key and press the Space bar. Now type Google Chrome and the browser should be listed.