PayerErrors.email

The email property is included in a PayerErrors object if the PaymentResponse.payerEmail property failed validation; in this case, the property should contain a string describing how to correct the problem. If the payer's email address passed validation, this property is not included in the PayerErrors object.

payerEmail = payerErrors.email;

If validation of the payer's email address (PaymentResponse.payerEmail) found problems, this property should be set to a DOMString that explains the validation problem and how to correct it. If the email address is valid, this property should be omitted from the PayerErrors object.

function validatePayment(response) {
  const correctionPromises
  let paymentErrors = {};
  let payerErrors = {};

  // Check payer details

  if (!validEmail(response.payerEmail)) {
    payerErrors.email = "Please make sure you enter a valid email address."
  }
  if (!validName(response.payerName)) {
    payerErrors.email = "Please enter a valid name, using only <appropriate characters>."
  }
  if (!validPhone(response.payerPhone)) {
    payerErrors.phone = "Please enter a valid phone number in the form ###-###-####."
  }

  // Check everything else too...

  //
}