Small JS snippet to use via console to check gpay availability

checkGPay.js

var e = document.createElement("script");
e.src = "https://pay.google.com/gp/p/js/pay.js";
document.head.appendChild(e);

e.onload = function(){

  var paymentsClient = new google.payments.api.PaymentsClient({environment: 'TEST'});

  var allowedPaymentMethods = ['CARD', 'TOKENIZED_CARD'];

  paymentsClient.isReadyToPay({allowedPaymentMethods: allowedPaymentMethods})

    .then(function(response) {

      if (response.result) {

        console.log("isReadyToPay: " + response.result);
      }

    })
}