JSON serialization while using class inheritance c#

Question

I am reading a json file that contains array of pets. Then I am creating list of PetBase that contains these pets. I am not sure how to write proper serializer for this. The customSerializer should init the proper child class and return that class. The json contains a field called type that tells us what kind of pet we got currently..so we can initialize the proper object type.

This is the doc that is close to what I want to do but not able to get it done. https://www.newtonsoft.com/json/help/html/CustomJsonConverter.htm

This is the Newtonsoft 'ToObject' method I am using and unable to find example of https://www.newtonsoft.com/json/help/html/M_Newtonsoft_Json_Linq_JToken_ToObject__1_1.htm

JObject o1 = JObject.Parse(File.ReadAllText(@"path")); 
CustomSerializer customSerializer = new CustomSerializer();
JsonSerializer jSerializer = new JsonSerializer();
jSerializer.Converters.Add(customSerializer);

//this following line errors out in CustomSerializer Class               
var listOfPets = o1["allPets"].ToObject<List<PetBase>>(jSerializer );

Here are the sample classes:

public class PetBase {
    string Name;
    string Age;
}

public class Dog:PetBase
{
    public string bark{get;set;}
    public string Bark() {
        return bark;
    }
}

public class Cat : PetBase
{
    public int lives{get;set;}
    public int HowManyLives() {
        return lives;
    }
}

Sample Json

{
  "allPets": [
    {
      "type": "cat",
      "lives": 10
    },
    {
      "type": "dog",
      "bark": "woof" 
    }
  ]
}

Custom Serializer

public class CustomSerializer: JsonConverter
{
    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        throw new NotImplementedException();
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
         //program fails here saying  
          //Newtonsoft.Json.JsonReaderException: 'Error reading JObject from JsonReader. 
         //Current JsonReader item is not an object: StartArray. 

         JObject jsonObject = JObject.Load(reader);  <------------------
         var properties = jsonObject.Properties().ToList();

         //not tested bellow..but this is the idea...
          if(properties["type"]=="dog") 
             return new Dog():              
          if(properties["type"]=="cat") 
             return new Cat():

    }
}