Editing Checkout Address Information

-- url of the page with the problem -- : 6bs.com.au/6bs-products/checkout
-- HikaShop version -- : 4.4.2
-- Joomla version -- : 3.9.26
-- PHP version -- : 7.3.27

The default address information in the checkout is as follows
Post Code is optional and phone is required.

Title*
First name*
Last name*
Address*
Post code
City*
Telephone*
Country*
State*

I'd like to resort and make Post Code compulsory, phone optional and resort as below

Title*
First name*
Last name*
Address*
City*
Post code*
State*
Country*
Telephone

What do I need to edit to put this into effect?
I have edited the Address & Shipping Format but nothing changes.

Thanks