Just writing small program how the qr code work and test
You need to figure out how the actual QR code portion is going to work and write the code that deals with them.
Here are links to other ionic apps using barcode/qr code scanners:
https://www.thepolyglotdeveloper.com/2014/09/implement-barcode-scanner-using-ionic-framework/
https://forum.ionicframework.com/t/how-to-display-encoded-qrcode-in-view/16869
https://ngcordova.com/docs/plugins/barcodeScanner/