here is what I found @ install ext-zip for Mac
I had the same problem after updating my Mac to Catalina. Here is what worked for me.
brew update
brew install php@7.3
brew link php@7.3
Then reload your console.
It will install PHP 7.3.10 with the zip module. You can use PHP -v to check for the version, and PHP -m for the modules.
Side note: in case you don't have Homebrew (brew) installed
you can visit: https://brew.sh/
A basic install of Homebrew (brew)
/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
Paste that in a macOS Terminal prompt.
