How to use RegEx in forumula

Hi, I’m new to Mockaroo. I want to use regex to generate test data as described here. I set up a field with Field Name of “phone” and Type of “Formula”.

I’m at a loss as to what to enter in Options (using a single digit \d character to test). I’ve tried:

  • /d
  • /d\
  • “/d”
  • (/d)

I get various errors and outputs from this. Can anyone help me get started?

I was being a dufus. I didn’t notice there is a Type called “Regular Expression”. Doh!