Apple introduced AppClips with a lot of documentation.
One of the options to invoke this AppClip is by scanning a QR code, here's a sample from Apple:
However, I can't find any info on how to create these kinds of codes.
Where can I find this information?
Creating App Clip Codes is now available through App Store Connect or using an App Clip Code Generator tool.
More information can be found here: https://developer.apple.com/documentation/app_clips/creating_app_clip_codes