Auto-increment field for channel entries

Hi all,

There used to be a plugin/fieldtype for this, but I think it has been discontinued.

What I am trying to achieve is the following:

I have moved a manual Excel receipt book to integrate with an EE system. Each payment that is received gets receipted with name, date, payment method etc.

The thing I am trying to get to work, however, is the auto-increment for the “receipt number” field.

I don’t want the user to have to manually enter in a new receipt number each time - It needs to just automatically be one more than the previous receipt number.

Note: I can’t use the entry ID, as they auto-increment across multiple channels.

Is anybody able to point me in the right direction to achieve this?

Thanks 😊