How to send Whatsapp messages without saving the number

Following steps to be follow

1. Open the web browser and then paste ‘https://api.WhatsApp.com/send?phone=number’ in the Address bar of your phone’s browser.
2. In the place of “number”, enter the phone number of the person to whom you want to send a WhatsApp message with the country code.
3. Omit any zeroes, brackets or dashes when adding the phone number in international format.
4. The number that you provided should have a WhatsApp account.
5. Click on “Message” button.
6. You will be taken to the WhatsApp app with a chat being open for the said contact.

for e.g. https://api.WhatsApp.com/send?phone=919820562897