1. First of all you have to open WhatsApp and click on the three Dots.
2.  Here you will see the option of Payments, on which you have to click to proceed.
3.  Then you will be asked to link your Bank Account.
4.  Because you are the new user of WhatsApp Payment Service, so Whatsapp will ask you to agree some of the Terms & Conditions when you click on Add New Bank account.
5. You have to verify your Mobile number after you agree terms and conditions.
6. After verifying phone number, the process of UPI verification starts.
7. Here you have to be sure that, your WhatsApp number and the number linked to your bank account is same.
8. After the verification is done, a list of various banks will appear in front of you in your Android phone.
9. Then click on the name of the bank in which you have activated UPI.
10. You will be then required to create VPA ie. Virtual Payee Address.
11. Then you will be asked to add some more information like, Last six digits of your Debit Card.
    After filling all this information, Click on the Submit Button.

Now you are done with all steps of transferring money through WhatsApp pay on your Android and the money will be transfer to your selected contact.