Please edit your post and format your pasted config and data as per point 11 here.
Anyway, I pasted the json data you provided into the left side of this site: https://jsonpathfinder.com/
Then I had to replace all the fancy quotes “” with straight quotes "" in a text editor and try again (because you did not format your data as above).
Then I drilled down on the right hand side to obtain this path (at the top of the right hand side column):
x.event.data.temperature.value
So you need:
state: "{{ trigger.json.event.data.temperature['value'] }}"
The value on the end has to be in square bracket notation as that word has special meaning in templates (but you already had that bit sorted).