Whats the point of Flipkart sparks when people can't pay at all
Flipkart neither allows you to input your UPI ID nor provides a one-click option to open Slice for transaction payments on iPhone or the web.
Slice should collaborate with Flipkart to enable its use for iPhone users.
This issue is not specific to Sparks; in general, Slice UPI cannot be used for regular transactions on Flipkart at all.