AbleCommerce Shopping Cart Software

We are currently running AbleCommerce R10 and would like to add Address Verification to reduce shipping errors.
We are setup with UPS for address verification, unfortunately I see that UPS Address verification wasn't added until R11, so it is not available in our version.

However, I see that AbleCommerce has supported USPS Address Verification since R3.
But when I follow the instructions for USPS integration it says to
Unfortunately, that URL does not work.

Is there another URL we can use to register for USPS Address Verification?

Alternatively, are there any plugins etc to support UPS address verification in R10?

My guess would be the Register Now button here
https://www.usps.com/business/web-tools ... elcome.htm
which leads to here
https://registration.shippingapis.com/

Thanks. I got registered through that URL and enabled on my development environment.
However, I'm not exactly sure when the address verify pops up.

I tested checking out as a guest, and using OnePageCheckout, I wasn't prompted after I set an incorrect zip code in shipping or billing address.

See if it works on EditBillAddress. I know it works there in R9 but it doesn't work on the OPC in R9. It uses IAddressValidatorService, and I see that on R11 EditBillAddress, but I don't see it on the one page checkout pages.