Is there a way that I can send a whatsapp attachment using PHP or a Laravel package?
And is it official API?
Generally, you would need permission to access the intended server for this type of work involving a third-party application. If granted, the next thing is to send a request based on your need and the given API options.
I could find CHAT-API through a quick search specifically designed to manipulate data for WhatsApp. You need to establish your initial connection, then register your number and follow the instructions in the Wiki.