This is what the document says:
1. Temporary QR codes have an expiration time. They can be set to expire up to 30 days (i.e. 2592000 seconds) after the QR code is generated, but a larger number can be generated. Temporary QR codes are mainly used in business scenarios such as account binding that do not require permanent storage of QR codes. 2. Permanent QR codes have no expiration time, but the number is small (currently up to 100,000). Permanent QR codes are mainly used in scenarios such as account binding and user source statistics.
1. Temporary QR codes have an expiration time. They can be set to expire up to 30 days (i.e. 2592000 seconds) after the QR code is generated, but a larger number can be generated. Temporary QR codes are mainly used in business scenarios such as account binding that do not require permanent storage of QR codes. 2. Permanent QR codes have no expiration time, but the number is small (currently up to 100,000). Permanent QR codes are mainly used in scenarios such as account binding and user source statistics.