Postal code

My business is a local business, my e-commerce is used to take orders for products that will then be delivered directly by me. I need to make sure that the users who visit the site before ordering place their Postal Code to see the service is available in their area. Does anyone know how I can do it?

You can set-up shipping by postal codes however this option is only available for the US and Canada and you must also be on the Advance Commerce plan.

https://support.squarespace.com/hc/en-us/articles/205811238-Creating-shipping-zones#toc-choose-shipping-zones

Maybe deliverychecker would work for you if you're ok using a 3rd party app - https://deliverychecker.co