OpenIn by Loshadki, LLC

Requires the OpenIn app for Mac, version 4.3 or later, available on the Mac App Store, Setapp, and loshadki.app.

What is OpenIn?
OpenIn is a Mac app that lets you choose which browser or app opens every link you click. It works with browser profiles, so your own rules can send each link to a specific browser, profile, or app.

Firefox add-on features

• Toolbar button
  Send the current page to OpenIn. It follows your rules or shows the app picker, so you can open the page in another browser, profile, or app.
• Context menu
  Right-click a link and choose “Open in OpenIn” to send it on without leaving the page.
• Automatic link handling
  In the extension settings, choose whether links to other websites go to OpenIn automatically, only when you hold modifier keys while clicking, or never. You also choose how domains are compared to decide which links count as external.