Whatsapp Automation Software

I am looking for a talented freelancer who can develop a Whatsapp automation software for my business. The main purpose of this automation software is for Integrarion with my another softwares and marketing. The essential features required for this software include the ability to send Bulk Messages and Automated responses with button and pdf/jpg/xlsx/zip files. Support also required after completing project to update regularly. Source code required for safety only.