MQTT Homeyscript

Can anyone help me with how I would store a value from an MQTT script in a variable?

I want to receive a message from an MQTT queue, my MQTT is /sensor/front-door/phone with a payload of
{“id”:“00:00:00:00:00:00”,“confidence”:“0”,“name”:"Phone ",“manufacturer”:“OnePlus Technology Shenzhen Co Ltd”,“type”:“KNOWN_MAC”,“retained”:“false”,“timestamp”:“Wed Nov 25 2020 21:41:16 GMT+0000 (GMT)”,“version”:“0.2.200”}
which I need to get the “confidence”:“0” value from (this changes based on connection)

I know I would need to use Homey Script, but unsure of even where this would start.