How do I activate UPI 123?

To activate UPI 123Pay on a feature phone, you can dial *99# from your phone. Next, select your bank, enter the last six digits of your debit card and its expiry date, and then set your UPI PIN. Alternatively, you can call one of the IVR numbers like 080 4516 3666, 6366 200 200, or 080 4516 3581 and follow the prompts to complete the activation process.