Addition two stages of the e-invoicing specifications for ksa to my application

e-invoicing specifications addition two stages of the e-invoicing specifications for ksa to my application two stages addition the e-invoicing specifications to my application ​​​​​​​​​​​​​​​​​BUSINESS AND TECHNICAL REQUIREMENTS (the Codeigniter PHP framework). Full specifications are available here: https://zatca.gov.sa/en/E-Invoicing/SystemsDevelopers/Pages/E-Invoice-specifications.aspx 2- Linking the application with the payment gateway CrediMax Payment Gateway As a payment method . You can review the link provided by the local payment gateway: https://credimax.gateway.mastercard.com/api/documentation/integrationGuidelines/index.html Note: I have already this Payment methods available on my script whmcs.