youtube-dl

Automator

You can run youtube-dl directly from any web browser (or any other application) using macOS services and Automator.

Choose Applications | Automator and then create a new Service (click the Service icon.)

Set the drop-down lists as shown below, pass input 'as arguments'

The Shell script can just be two lines, one to cd change directory to where you want the movie saved, and the second to run youtube-dl passing the URL.

With that done save the Automator Service with a suitable name like "Save Youtube Movie"

To run this, select any URL, in the web browser address bar, or even just a suitable url within a text document, then go to the services menu and select the name of your Automator service "Save Youtube Movie".

(Automator Services are automatically saved to ~/Library/Services/ )