MQTT is not publishing single topics, but Object that Node-RED/InfluxDB can't parse?

I want to use MQTT to visualize the power consumption of a device plugged into my Shelly Plus Plug S. But it appears that it's publishing only a single MQTT topic containing a bunch of information. The topics name is shellyplug/status/switch:0 and contains the following:

{"id":0, "source":"init", "output":true, "apower":26.2, "voltage":232.1, "current":0.179, "aenergy":{"total":3314.509,"by_minute":[436.678,435.823,438.814],"minute_ts":1690747019},"temperature":{"tC":33.5, "tF":92.3}}

Unfortunately Node-Red and InfluxDB can't parse this information. Node-Red is giving me the following error:

Error: A 400 Bad Request error occurred: {"error":"unable to parse 'apower aenergy=[object Object],apower=26,current=0.177,id=0,output=true,source=\"init\",temperature=[object Object],voltage=232.3': invalid boolean"}

What am I missing?

Thanks I do speak German, but this unfortunately doesn't help. I just need the value "apower":26.2 from the message and don't know how to do that.