csharp class adding object

Question

I need to POST to API server like following

with extra field "UserObj"

Json from postman

{

"CompanyCode": "tkf",

"YardNumber": "01",

"UserObj":{

"LotNumber": "9003",

"PenNumberOriginal": "330",

"HomePenNumber": "330",

"PenNumberDeathPen": "HSP2",

"InError": false,

"CodeDesc": "ACIDOSIS",

}

}

how can arrange my ListFields class so make it jason way

so far I have done

var queryPram = new QueryPram()

{

CompanyCode = "abc",

YardNumber = "01",

"DeadsObj" = new ListFields

{

LotNumber = "9003",

PenNumberOriginal = "330",

HomePenNumber = "330",

PenNumberDeathPen = "HSP2",

"InError": false,

"CodeDesc": "ACIDOSIS"

},

IsReversal: false

};

is not working can some please help me correct the queryPram object

Any help will be really appriciated