Send Dictionary to Firebase DB

I want to send a Dictionary<string, string> to Firebase DB, where the first element is the Key and the second string is the Value, but I get an error.

I currently have:

`Dictionary<string, string> list = new Dictionary<string, string>();
list.Add("Name", "John")

await firebase
.Child("x")
.PutAsync(JsonConvert.SerializeObject(list));

`

but I don't get a result.