The QR code was invented by a Japanese company, DENSO WAVE (DENSO at the time of invention). Although DENSO owns several related patents, it has decided not to exercise the rights in order to standardize QR code. Nowadays, we can see QR code in various places.
The QR code that links to the GO TOKYO tourist information site, appears even on the back of the uniform worn by the Tokyo Tourism Volunteers. (See below image)
A QR code that is capable of being read in 360 degrees, is made of multiple rows and columns and a position marker is placed at the three corners of the QR code.
As long as we follow the regularity prescribed by patents owned by DENSO WAVE, you can create free QR codes.