Your QR code is always there in Paytm with Business App in the “Accept Payments” tab. You can ask your customers to scan it from there directly.
If you need to print your QR code, you can download it and print it. You can also order your physical QR code via your Business with Paytm app.
If you have ordered a QR code through your app, it is very important to link your ordered QR code before you start taking payments.