You will only need to scan a new QR code if you change mobile devices.
To change devices, log in to your Okta dashboard on a computer. Click on the Account button in the lower left-hand corner to find the Extra Verification section. In this section, find and click the Reset button next to the Okta Verify mobile app. A warning message will appear to alert you that you will be reconfiguring your multifactor authentication. Click yes to proceed and select the new mobile device operating system you are using (iPhone or Android). Click next and select the Account button, then select Scan Code to pull a new QR code up on your screen. Using the camera on your mobile device, focus the camera on the QR code. Once your device recognises the QR code, you will see six numbers appear on the screen. On the computer, click next, and enter the code from your device. Finally, click verify. Then click done and you're ready to go!