The way QR codes work is that each unique design is connected to a unique URL. There are two types of QR codes, static and dynamic, a static code is programmed to lead to one specific URL and the destination can never be updated. On the other hand, all Flowcodes are dynamic, which means the destination can be updated as often as you'd like, this is because the URL linked to the code design is a redirect URL rather than the final intended scan destination, commonly a website or file.
We aren't able to migrate already existing QR codes as we don't own the unique URLs associated with other companies' QR code designs.
Please let us know if you have any further questions, you can learn more about each specific tier at https://www.flowcode.com/plans.