1. If you want to make the UPI mandate payment via BHIM app, you need to open BHIM on your phone and click on the IPO which is usually listed on the main screen itself. 

2.  You can also look for a section called 'Mandates' which is on main screen itself.

3.  Here, you will see your ‘Active’ and ‘Pending’ mandates

4.  Click on ‘Proceed’ by entering your UPI PIN to complete your application. It will show you the screen with details like Application No., Mandate validity, Frequency and amount.