On your Accounts Screen (the page you land after launching the app), right below your account cards, there will be a row with navigation buttons. Tap on the Pay button to be taken to the Scan Screen. All you need to do then is to position your device’s camera over the QRCode of the person who is requesting the payment and TronWallet will take care of the rest. You will be asked to provide your PIN number. Then, with the proper PIN, you will be taken to a Success Screen which indicates your payment was successful.
Help & Tutorials: https://medium.com/tronwallet-support