I also ran into this issue today. Use the following code in <script> tag. It will work for you.
var form = document.querySelector('#hosted-fields-form');
var submit = document.querySelector('input[type="submit"]');
braintree.client.create({
authorization: '<YOUR_TOKENIZATION_KEY>'
}, function (clientErr, clientInstance) {
if (clientErr) {
console.error(clientErr);
return;
}
braintree.hostedFields.create({
client: clientInstance,
styles: {
'input': {
'font-size': '14px'
},
'input.invalid': {
'color': 'red'
},
'input.valid': {
'color': 'green'
}
},
fields: {
number: {
selector: '#card-number',
placeholder: '4111 1111 1111 1111'
},
cvv: {
selector: '#cvv',
placeholder: '123'
},
expirationDate: {
selector: '#expiration-date',
placeholder: '10/2019'
}
}
}, function (hostedFieldsErr, hostedFieldsInstance) {
if (hostedFieldsErr) {
console.error(hostedFieldsErr);
return;
}
form.addEventListener('submit', function (event) {
event.preventDefault();
hostedFieldsInstance.tokenize(function (tokenizeErr, payload) {
if (tokenizeErr) {
console.error(tokenizeErr);
return;
}
console.log('Got a nonce: ' + payload.nonce);
$.ajax({
type: 'POST',
url: '<YOUR_API_URL>',
data: { 'paymentMethodNonce': payload.nonce }
}).done(function (result) {
hostedFieldsInstance.teardown(function (teardownErr) {
if (teardownErr) {
console.error('Could not tear down Drop-in UI!');
} else {
console.info('Drop-in UI has been torn down!');
$('#submit-button').remove();
}
});
if (result.success) {
$('#checkout-message').html('<h1>Success</h1><p>Your Drop-in UI is working! Check your <a href="https://sandbox.braintreegateway.com/login">sandbox Control Panel</a> for your test transactions.</p><p>Refresh to try another transaction.</p>');
} else {
console.log(result);
$('#checkout-message').html('<h1>Error</h1><p>Check your console.</p>');
}
});
});
}, false);
});
});