How can I monitor the switch-on time of a solar powered electric boiler and top it up if it is too short?

I duckduckgoed homewizzard energy socket and could only find homewizard with one z. I presume it's the right device.

Many folk like to interface their smart devices with Node-red via MQTT I don't see any indication that the homewizard can do this, but it does have an API which you can presumably interrogate through an http request.
You might find some useful info in this forum post.

And of course one reason to run Home Assistant is that it can interface with lots of devices.

How? Is there any documentation anywhere for this? What data can you access?