You're basically out of luck. This is happening all over the world these days with various government services.

It's not just for clients with no smart phones. It's also clients who activate developer mode on their smartphone etc... clients who use VPN. Clients who run AdBlocker. Clients who use Firefox.

There needs to be a severe push back against this.

Things have gotten so crazy that the homeless here are walking around with QR codes printed out when begging for money. I'm guessing they're a network of people who share the same smartphone/payment method..

They're 50/50 to either make it work or fire you as a customer - you may as well try.