is it possible to send a whatsapp message to a specific whatsapp account (phonenumer) which is not stored in contact book?
wanna set a whatsapp url scheme on my website to provide a direct contact via whatsapp.
No, it's not possible to send someone a message using WhatsApp without storing the number in Contact Book. And the reason for that is exactly what you're trying to do: WhatsApp won't allow you to send random numbers 'spam'. You'll have to collect numbers and add them to your contacts and then send them a message manually.