Gav_in:
The Data List you have above is from your Collector / Logger not the Inverter…(and FWIW matches the structure of my own so you are doing this correctly for the collector).
You need to run the final Curl command in the instructions twice with the different serial numbers of your devices to get the data you want…once for Collector with its serial number, and again separately for the Inverter with its serial number. The AppID and Bearer Token remain the same, just change the serial number each time.
One you have proof of concept, then create separate rest sensors as required depending on whether you want the whole list or a selection only…
Did a quick test and changed the Device SN to SE1ES430N5R577 (invertor) and got the date that was needed. Did not get that bit of info from the instructions. Will play again and further with this info.