Checkout Forms with PayPal

When using a PayPal payment gateway, PayPal has its own submit button.

You need to:

1) Hide the normal form submit button

2) If you wish to use a custom error function for the form, set a JavaScript global variable like this:

window.s_e_paypal_error = () => {
  //do something
}

See Forms Error Callback and Validation

Custom success functions are not yet supported for PayPal.