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 ( The country is specified in the system settings page. If the country is set to Saudi Arabia , the Zakat specifications will be work, but if set to another country, Zakat specifications it will be not work.) 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 Note: The income and zakat specifications must work if the merchant's country is set to (Saudi Arabia). If the country is not Saudi Arabia, it will be disabled and will operate in the system's default state. 2- Linking the application with the payment gateway CrediMax Payment Gateway As a payment method With the addition of a table to save payment data for use in the next fast payment process by default. 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. 3-Adding everything necessary to register the new customer through the application and website using modern methods / specifying the subscription type / subscription period / system type / mobile number verification / email verification / after the payment process, converting the account status from inactive to active. Provide the complete source code files.