Send message to number not in contact

[derodevil]

How can I send message to phone number where it's not in the contact list? When the destination number in the contact or the number sent my me first I can send it back

[derodevil]

Using this technique is very slow:

IJavaScriptExecutor js = driver as IJavaScriptExecutor;
                js.ExecuteScript("window.location.href = 'https://web.whatsapp.com/send?phone=" + number + "'");

I have to wait until a popup element is shown. It takes around 4 seconds with a good internet connection.

[ZetDeveloper]

It is a good option to use that technique if you want to avoid banning, I'm working on a more efficient method but the reverse engineering process is complex.