using System;

using System.Text.Json;

public class Program

{

    public static void Main()

    {   

        var inputJson = "{\"issuer\":{\"address\":{\"branchID\":\"\",\"country\":\"\",\"governate\":\"\"}}}";

        var stringifiedJson = "{\"documents\": [" + inputJson + "]}";   

        Console.WriteLine(JsonSerializer.Serialize<dynamic>(stringifiedJson, new JsonSerializerOptions() {WriteIndented = true}));

    }

}