how to create a records array for upsertRecord

Hi I need to create an $recordsArray to usert my record, currently i am using json_encode to convert my php array to json,

 
   try {
  
   $recordsArray = [
   "data" => [
  
   "First_Name" => 
   "fname",
  
   "Name" => 
   "lname",
  
   "Email" => 
   "badboy@gmail.com"],
  
    ];
  
   var_dump(
   json_encode(
   $recordsArray, JSON_PRETTY_PRINT));
  
   $zcrmModuleIns = 
   ZCRMModule::
   getInstance(
   "contacts");
  
   $bulkAPIResponse = 
   $zcrmModuleIns->
   upsertRecords(
   json_encode(
   $recordsArray)); 
   // $recordsArray - array of ZCRMRecord instances filled with required data for upsert.
  
   $entityResponses = 
   $bulkAPIResponse->
   getEntityResponses();
  
   foreach (
   $entityResponses as 
   $entityResponse) {
  
   if (
   "success" == 
   $entityResponse->
   getStatus()) {
  
   echo 
   "Status:" . 
   $entityResponse->
   getStatus();
  
   echo 
   "Message:" . 
   $entityResponse->
   getMessage();
  
   echo 
   "Code:" . 
   $entityResponse->
   getCode();
  
   $upsertData = 
   $entityResponse->
   getUpsertDetails();
  
   echo 
   "UPSERT_ACTION:" . 
   $upsertData[“action”];
  
   echo 
   "UPSERT_DUPLICATE_FIELD:" . 
   $upsertData[“duplicate_field”];
  
   $createdRecordInstance = 
   $entityResponse->
   getData();
  
   echo 
   "EntityID:" . 
   $createdRecordInstance->
   getEntityId();
  
   echo 
   "moduleAPIName:" . 
   $createdRecordInstance->
   getModuleAPIName();
  
    }
  
    }
  
    } 
   catch (
   ZCRMException 
   $e) {
  
   //var_dump($e);
  
   echo 
   $e->
   getCode();
  
   echo 
   $e->
   getMessage();
  
   echo 
   $e->
   getExceptionCode();
  
    }

I am getting 400 Invalid Data everytime I anybody please provide with an example to do the upsert record. I have already gone through the documentation and tried everything.