title: how to autogenerate transaction ID during checkout in Opencart?
body: <p>I am trying to integrate a payment gateway (www.sslcommerz.com.bd) in Opencart  which requires to submit a transaction id at the time of checkout. This transaction id needs to be stored in the database and The gateway will save the Transaction ID for any sort of future queries and cross checking with online store system for verification of payment completion. I am new to Opencart. can anyone please give some idea how should I approach to achieve that? thanks in advance. </p>