Problem decode CayenneLPP

Problem decode CayenneLPP

Hi. I have problem with data arived in Tago.IO
So , the entire messages is:
[ { "variable": "frequency", "value": 868300000, "serie": 1707670203820 }, { "variable": "modulation", "value": "LORA", "serie": 1707670203820 }, { "variable": "bandwidth", "value": 125, "serie": 1707670203820 }, { "variable": "spreading_factor", "value": 7, "serie": 1707670203820 }, { "variable": "code_rate", "value": "4/5", "serie": 1707670203820 }, { "variable": "polarization_inversion", "value": false, "serie": 1707670203820 }, { "variable": "fCnt", "value": 14, "serie": 1707670203820 }, { "variable": "fPort", "value": 10, "serie": 1707670203820 }, { "variable": "deviceName", "value": "Test2", "serie": 1707670203820 }, { "variable": "adr", "value": false, "serie": 1707670203820 }, { "variable": "dr", "value": 5, "serie": 1707670203820 }, { "variable": "objectJSON", "value": "{\"analogInput\":{\"0\":25.3,\"1\":65.5,\"2\":4.92}}", "serie": 1707670203820 }, { "variable": "confirmedUplink", "value": false, "serie": 1707670203820 }, { "variable": "payload", "value": "000209e201021996020201ec", "serie": 1707670203820 }, { "variable": "application_id", "value": "2", "serie": 1707670203820 }, { "variable": "application_name", "value": "app", "serie": 1707670203820 }, { "variable": "device_name", "value": "Test2", "serie": 1707670203820 }, { "variable": "device_eui", "value": "6081f9741a7b90ee", "serie": 1707670203820 }, { "variable": "dev_addr", "value": "008c3c69", "serie": 1707670203820 } ]

Problem it's with "objectJSON" variable. 
Variable "0" it is temperature
Variable "1" it is humidity
Variable "2" it is battery voltage.
Please, someone help me to make this variable available? At this momment i have "objectJSON" variable with exemple contet char "{\"analogInput\":{\"0\":25.3,\"1\":65.5,\"2\":4.92}}"
In gateway chirpstack messages appears ok 

So, please,  how can i solve the problem? Can someone help me with a custom paylod parser decoder?
Thanks you!