This is a simple website to create URLs that follow the Zoom URL scheme. You can save the converted URL in your calendar, notes, etc. Clicking them should open the Zoom app directly, so you don't need to open your browser.
A direct link saves you the hassle of having to open a new tab in your browser each time you want to open a Zoom join link — a particular nuisance if you have your Zoom links saved in a different application, like your calendar, notes, etc.