C# Json Convert any dynamic object to key value pairs not class

i have a Json

{
   "test1.png": "123",
   "image.png": "456",
   "pdffile.pdf": "789"
}

how can i convert to C# dictionary or table

>Solution :

How about this?

string serializedDic = @"{
   ""test1.png"": ""123"",
   ""image.png"": ""456"",
   ""pdffile.pdf"": ""789""
}";

Dictionary<string, string> dict = 
  JsonSerializer
  .Deserialize<Dictionary<string, string>>(serializedDic);