Create a PHP SagePay/Opayo custom amount payment script

Please read carefully before bidding. Automatic bids and copy and paste bids will be ignored. We would like to create a script that can take SagePay payments easily using SagePay API. ([login to view URL]) Based on an amount in url (for example: [login to view URL]) the customer can fill in their address details, and be transferred to the SagePay website to make payment. When they return to the website, the payment information must be stored in a MySQL database. The customer must return to the website before the payment is confirmed. If the customer does not return to the website, the payment must not be confirmed. The API is here: [login to view URL] I will provide testing API credentials and a MySQL database structure to work to. Requirements: 1) Experience in Payment Gateways 2) Experience in PHP & MySQL 3) Clean, well commented code with no frameworks 4) MySQLi please (not PDO) 5) Must be built within 4 days 6) Code must be as DRY as possible 7) Must be secure and 100% reliable Please comment "Understood" to show you have read the bid carefully. Please let me know about YOU as a person. I message genuine people, not copy and pasters :)