Thanks Martin for your swift response, I cloned your code v1.0.0 and this works fine!
I’ll continue with my project using this code instead.
The idea is that I send an orderID and containerID from a website via MQTT to the module linked to the containerID who then displays a QR code with “URL+’?orderid=’+orderID”.
When the customer scans the code he can confirm with a signed transaction the delivery of the goods and release the escrowed payments that are locked in a smart contract on Ethereum.
The project is used to demonstrate some innovative ideas in a logistics simulation game in our local university.