Getting data from URL

I am trying to create a sensor that extracts data from a URL. I know this is JSON data, but dont quite get how to process it, can someone give me some advice on this, the URL is

and the data that it returns looks like

  "liveRainfallLevelsData" : [ {
    "dateTime" : "2020-10-22 23:18:00",
    "currentRainfallLevel" : 0.00,
    "cumulativeRainfallLevel" : 0.00
  }, {
    "dateTime" : "2020-10-22 23:12:00",
    "currentRainfallLevel" : 0.00,
    "cumulativeRainfallLevel" : 0.00
(lots more of them)

I really just want the 3 pieces of data from the first one, which is the newest entry

Try like this:

  - platform: rest
    resource: ""
    name: Current Rainfall Level
    value_template: '{{ value_json.liveRainfallLevelsData[0].currentRainfallLevel }}'

Thanks, It creates the sensor, but it doesnt return any data image

There’s a typo in my post should be liveRainfallLevels not liveRainFallLevels, I corrected my post, please try again.

Yep that does it. I see how it works now, thanks again.

One last question, what would I add to get the timestamp as an attribute?

You could create a REST sensor that contains the three data points (current, cumulative, timestamp) instead of just the current level. And then extract them with a separate template sensor.