Related, this page has a step by step process of how the encoding process works:
https://www.nayuki.io/page/creating-a-qr-code-step-by-step
Previously discussed here:
https://www.nayuki.io/page/creating-a-qr-code-step-by-step
Previously discussed here:
Here you go: https://qrlogo.kaarposoft.dk/qrdecode.html