Desenvolver uma integração em WHMCS

Today I have a module that does billing payments by credit card within my WHMCS without leave to any external page. I need an experienced freelancer to develop a WHMCS automation integration in monthly payments of these invoices, WHMCS already has various settings for this automation, so I need someone who already knows the system. - I need a monthly billing invoice by credit card is done. - At the time of payment to have the option of the person wanting to save data automatically or no charge. - I need extreme security in the storage of such data. Amateur or waste time in contacting. Thank you