I want to hold a key (1), and for it to repeat every 0.5 seconds until I release it using 'Automator' or 'AppleScript'?

When I was on Windows, I used AutoHotKey to allow me to hold down the "1" key, and for it to simulate pressing it every 0.5 seconds until I let go.

I managed to do something in Automator (or AppleScript) on my old Mac to give me the same functionality, however I forgot to write down how I did it.

I am now on a new Mac and cannot fathom how I did it (Google doesn’t really help).

Any suggestions?