Assist me with Bulk Marketing

I need to create a simple script (im not sure thats what you name it) that enables me to send promotion text via web whatsapp or whatsapp desktop so i do not have to manually click/paste send. My content would be fixed (promotion text), and i already have my contacts saved. Would be a budget project, so i do not need complex programming. workflow would be: search contact-paste promotion text- send, then move on to next contact.