Just logged into the HeyYou app to redeem my $2 discount coffee but saw a banner about a free coffee when you add Visa checkout as a payment source. It did say new visa checkout customers only but I was an existing customer and it worked. Enjoy.
TLDR free coffee
Update: it looks like you don't need the banner.. Just add Visa checkout and you should see the discount in checkout.
Nothing better than a $2 coffee except a free coffee