In order to get UPI request notifications on your UPI Apps, please make sure you have enabled notifications for these apps on your Android/iOS settings.
Most UPI apps will send you an SMS with a link to open your UPI app and complete the payment requested from CoinSwitch. Sometimes these UPI apps don’t send SMS. Please do not wait for any SMS or Notification. You can just open the UPI App to which your Entered UPI ID is linked and you should see the payment request.