ApplePay canMakePaymentsWithActiveCard Promise returns false

Question

ApplePay canMakePaymentsWithActiveCard . Promise returns false on Mac Safari, but true for iPhone Safari. canMakePayments returns true for both. I am using the Apple Sandbox developer account with the test credit cards that Apple provided. Any idea why canMakePaymentsWithActiveCard returns false on Mac Safari?

if (window.ApplePaySession) {
    // I'm not posting actual merchantIdentifier due to security reasons
    var merchantIdentifier = 'my unique identifier';
    var promise = ApplePaySession.canMakePaymentsWithActiveCard(merchantIdentifier);
    promise.then(function (canMakePayments) {
        if (canMakePayments)
        // For some reason false on Mac Safari
    }); 
}