What is Earn?
Earn is a feature on PhonePe that lets you earn money by completing tasks such as referring apps to your friends and family or completing surveys. Once a task is completed, the amount earned will be added to your PhonePe Gift Card.
Related question(s)
With whom can I share app referrals?
How do I refer apps on PhonePe to someone?
How do I take a survey on PhonePe?