messengerapi.Client/code/MessengerApi.Client/Model/Credentials.cs

namespace MessengerApi.Model
{
    public class Credentials
    {
        public string ApiKey { get; private set; }

        public string ApiUrl { get; private set; }

        public Credentials(string apiKey, string apiUrl)
        {
            ApiKey = apiKey;
            ApiUrl = apiUrl;
        }
    }
}