Google Duo is a video chat mobile app developed by Google. Now Google has introduced Refer & Earn program.
Google Pay Rewards Program Terms and Conditions for Duo Invites in India
Maximum rewards per user = Indian Rupees Nine Thousand (INR 9,000) per financial year (1 April to 31 March) across all Google Pay offers.
You may earn Google Pay scratch card rewards for inviting your friends to join Duo during the offer period, once they accept the invite. In addition, they will earn Google Pay scratch card rewards themselves.
This offer is not available to the residents of the state of Tamil Nadu (as per Tamil Nadu Prize Scheme (Prohibition) Act 1979) and wherever else prohibited by Law. Residents of these States should not participate in this offer.