What are the values of status of a payment request?

Status of a payment request describes the state of a payment request.

1. Pending : This is the default status. The email and/or sms (whichever is applicable) have not been sent out yet.
2. Sent : The email and/or sms (whichever is applicable) has been sent.
3. Failed : The email and/or sms (whichever is applicable) were not sent successfully.
4. Completed : Payment was made by a customer.