Q. How do I pay using GCASH (QR)?

To use GCash QR using your smartphone simply:

1. Click on Pay QR on the main page.
2. Tap on the “Scan QR Code” Icon.
3. Align the camera at the cashier’s QR code.
4. Once the app detects and identifies the merchant, input the total amount of your purchase (amount to pay).
5. Confirm transaction details. Both you and the identified payment counter in the library will receive an SMS from 2882, which will serve as your receipt.

https://www.gcash.com/frequently-asked-questions/#58cd53bbc851abedf

Note: designated payment counters in The Learning Commons, HSSH: 6th floor, 7th floor, 8th floor, and 9th floor.