How can I submit a form with payload.nonce in client sdk? I'm using an example given by the Braintree?

I'm stuck at this point now. I never used braintree API before. The problem is when I hit the submit button it is showing alert box with my payment_method_nonce. It means I'm successfully getting the payment_method_nonce from the client, But the problem is I don't know how can I submit a the form with this payment_method_nonce. This client sdk is written in jquery. And I tried several ways to submit the form but I don't know exactly how can I get a 'payment_method_nonce' when submitting a form. I tired adding a hidden type field. And even that hidden type field doesn't comes up. Please help. Here is the jquery code. I just want to know how can I submit a form in jquery with that 'payment_method_nonce'.

    braintree.client.create({
  authorization: '{{$clientToken}}'
}, function (err, clientInstance) {
  if (err) {
    console.error(err);
    return;
  }

  braintree.hostedFields.create({
    client: clientInstance,
    styles: {
      'input': {
        'font-size': '14px',
        'font-family': 'helvetica, tahoma, calibri, sans-serif',
        'color': '#3a3a3a'
      },
      ':focus': {
        'color': 'black'
      }
    },
    fields: {
      number: {
        selector: '#card-number',
        placeholder: '4111 1111 1111 1111'
      },
      cvv: {
        selector: '#cvv',
        placeholder: '123'
      },
      expirationMonth: {
        selector: '#expiration-month',
        placeholder: 'MM'
      },
      expirationYear: {
        selector: '#expiration-year',
        placeholder: 'YY'
      },
      postalCode: {
        selector: '#postal-code',
        placeholder: '90210'
      }
    }
  }, function (err, hostedFieldsInstance) {
    if (err) {
      console.error(err);
      return;
    }

    hostedFieldsInstance.on('validityChange', function (event) {
      var field = event.fields[event.emittedBy];

      if (field.isValid) {
        if (event.emittedBy === 'expirationMonth' || event.emittedBy === 'expirationYear') {
          if (!event.fields.expirationMonth.isValid || !event.fields.expirationYear.isValid) {
            return;
          }
        } else if (event.emittedBy === 'number') {
          $('#card-number').next('span').text('');
        }

        // Remove any previously applied error or warning classes
        $(field.container).parents('.form-group').removeClass('has-warning');
        $(field.container).parents('.form-group').removeClass('has-success');
        // Apply styling for a valid field
        $(field.container).parents('.form-group').addClass('has-success');
      } else if (field.isPotentiallyValid) {
        // Remove styling  from potentially valid fields
        $(field.container).parents('.form-group').removeClass('has-warning');
        $(field.container).parents('.form-group').removeClass('has-success');
        if (event.emittedBy === 'number') {
          $('#card-number').next('span').text('');
        }
      } else {
        // Add styling to invalid fields
        $(field.container).parents('.form-group').addClass('has-warning');
        // Add helper text for an invalid card number
        if (event.emittedBy === 'number') {
          $('#card-number').next('span').text('Looks like this card number has an error.');
        }
      }
    });

    hostedFieldsInstance.on('cardTypeChange', function (event) {
      // Handle a field's change, such as a change in validity or credit card type
      if (event.cards.length === 1) {
        $('#card-type').text(event.cards[0].niceType);
      } else {
        $('#card-type').text('Card');
      }
    });

    $('.panel-body').submit(function (event) {
      //event.preventDefault();
      hostedFieldsInstance.tokenize(function (err, payload) {
        if (err) {
          console.error(err);
          return;
        }
        // This is where you would submit payload.nonce to your server
        alert('Submit your nonce to your server here!' + payload.nonce);
      });
    });
  });
});

_{Full disclosure: I work at Braintree. If you have any further questions, feel free to contact support.}

Without your form, or HTML code included, it's tough to know if you've defined your form as a variable. Essentially, though, you'll want to inject that nonce value (payload.nonce) into your form, following which you'll submit that form to your server.

For example, I have defined my form (above my braintree.client.create)

var form = document.querySelector('#checkout-form');

Then, in your submit event, you'll want to inject the payload value into your form after a successful tokenization (which you've seemed to achieve based on the alert value)

document.querySelector('input[name="payment_method_nonce"]').value = payload.nonce;

Subsequently submitting your form;

form.submit()

This will submit your form with an input named payment_method_nonce, which you can then request on your server.

Let me know if I can further clarify. Happy to help.