How do I easily generate a new Hide my Email in Safari on my Mac?

Hi, I can go into the settings and manually create a new Hide My Email address but is there an easier way when filling in a registration form on a website?

The help suggests there should be an Hide My Email option when I click in an email field but it does not seem to be working or at least I'm not seeing how to make it work.

Is there there something I need turned on?

Thank you for your help.