Do we deliver to your postcode lookup

Site URL: https://home-cooked.squarespace.com/config/

I'm trying to work out easiest way for customers to be able to enter their postcode (Australia) to show if we can deliver to them. Any integrations or suggestions anyone can offer is greatly appreciated. 

*please note this site is still being built

A member recently contacted me to ask about this, this is an example I quoted him. https://otto-pantry.net/

I used Js code.

Hopefully there will be a third tool that has supported this. ✌️