How do I send a WhatsApp message to a number
that does not exist in my contacts?

Just enter the number you want to send here, with the country code, without +.
that's it.

?

No spaces, no hyphen, no plus.
Only country code and phone number.
This number: +1 (442) 999-9999.
Will be written like this: 14429999999.

You can also copy the Html link and paste on your web site.