Read water usage via MQTT

I’m using a P1-dongle with watermeter (Producten - Smartstuff). The device is MQTT capable, see MQTT | Handleidingen
There is a message for the read out of watercosumption: water_delivered. /* FixedValue */
My question is: how can I get this value into my Homey Pro. My goal is to read the daily consumption as well as the total meter reading.
As you may have noticed, I’m a layman in the MQTT area, and I would be grateful for any help.

Maybe this tutorial will help you:

[Tutorial][Pro] How to integrate Hoymiles Microinverters via OpenDTU and MQTT