Change admin and 1234 in the URL to your username/password values. Make sure they are URL-encoded.
Change 192.168.23.5:12345 to your IP-address/port number (192.168.1.XXX:80)
myStatus is a random trigger name; it connects the “GET” card with the “JSONpath waarde/value” card (when the GET request has been performed, it will look for trigger cards with that name and trigger them)
Create a virtual device of type “sensor” with (at least) the capability “Measured temperature”
I’m pretty sure the “#Temperature” tag isn’t the right one, because it’s not provided by the “JSONpath value” card. In my case, the tag that contains the temperature value is called “value numerical” (or something similar, I only see the Dutch translation).
In the dialog where you pick the tag, the tags related to that flow are shown at the top: