Hi RidgelineLaw,

The custom field feature which you speak about is only available on Quickbooks Advanced which is a US only subscription not available to Australian users for the time being.

The photo in the link you have provided is of a US subscription of Quickbooks Online.

If this is something you would like to see in the future, I would urge you to provide this feedback within the product itself by going to Settings (cogwheel) > Feedback.

I hope this clears things up for you.

Kristian.