Limit Address Selection

-- url of the page with the problem -- : valentinosafeco.com.au
-- Joomla version -- : 3.10.2

How can I limit the available addresses in the Checkout?

Example:

The shop is set to Australia and I get all states in a drop-down or list, i.e.:
ACT
NSW
VIC
SA
NT
TAS

and so on.
How can I limit this to just one state - say TAS?

Many thanks for your support in advance.

Best,

Thomas

I figured it out.

It is as simple as editing the sub zones.

Thanks