Account Manager for using Firebase with FirebaseAuthentication.net library

AccountManager.cs

class AccountManager
    {
        private static AccountManager mInstance;
        public static FirebaseAuthProvider mAuthProvider = new FirebaseAuthProvider(new FirebaseConfig("firebase_api_key"));
        public FirebaseAuthLink mAuthLink;
        public static bool IsSignOut = false;

        public static AccountManager Instance()
        {
            if (mInstance == null)
                mInstance = new AccountManager();

            return mInstance;
        }

        public async Task<bool> Refreshable()
        {
            try
            {
                var auth = new FirebaseAuth();
                auth.FirebaseToken = Properties.Settings.Default.token_txt;
                auth.RefreshToken = Properties.Settings.Default.refresh_token_txt;

                mAuthLink = await mAuthProvider.RefreshAuthAsync(auth);
                mAuthLink = await mAuthLink.GetFreshAuthAsync();
                mAuthLink.FirebaseAuthRefreshed += AuthLink_FirebaseAuthRefreshedAsync;

                await mAuthLink.RefreshUserDetails();

                if (string.IsNullOrEmpty(mAuthLink.FirebaseToken))
                    return false;

                if (mAuthLink.User == null)
                    return false;

                IsSignOut = false;

                return true;
            }
            catch (Exception e)
            {
                MessageBox.Show(e.ToString());
                return false;
            }
        }


        public async Task<bool> SignIn(string email, string password)
        {
            try
            {
                mAuthLink = await mAuthProvider.SignInWithEmailAndPasswordAsync(email, password);
                var firebase = new FirebaseClient(
                      "firebase_site",
                      new FirebaseOptions
                      {
                          AuthTokenAsyncFactory = () => Task.FromResult(mAuthLink.FirebaseToken)

                      });

                Properties.Settings.Default.email_txt = mAuthLink.User.Email;
                Properties.Settings.Default.token_txt = mAuthLink.FirebaseToken;
                Properties.Settings.Default.refresh_token_txt = mAuthLink.RefreshToken;
                Properties.Settings.Default.Save();
                IsSignOut = false;

                // Idk why? but it must be executed
                await mAuthLink.RefreshUserDetails();
                mAuthLink.FirebaseAuthRefreshed += AuthLink_FirebaseAuthRefreshedAsync;

                return true;
            }
            catch
            {
                return false;
            }
        }

        public bool SignOut()
        {
            try
            {
                Properties.Settings.Default.email_txt = mAuthLink.User.Email;
                Properties.Settings.Default.token_txt = "";
                Properties.Settings.Default.refresh_token_txt = "";
                Properties.Settings.Default.Save();
                IsSignOut = true;
                return true;
            }
            catch
            {
                return false;
            }
        }


        private async void AuthLink_FirebaseAuthRefreshedAsync(object sender, FirebaseAuthEventArgs e)
        {
            Properties.Settings.Default.token_txt = e.FirebaseAuth.FirebaseToken;
            Properties.Settings.Default.refresh_token_txt = e.FirebaseAuth.RefreshToken;
            Properties.Settings.Default.Save();
            await mAuthLink.RefreshUserDetails();
            IsSignOut = !mAuthLink.IsExpired();
        }

        public async Task<bool> SignUp(string email, string password)
        {
            try
            {
                mAuthLink = await mAuthProvider.CreateUserWithEmailAndPasswordAsync(email, password);
                var firebase = new FirebaseClient(
                      "firebase_site",
                      new FirebaseOptions
                      {
                          AuthTokenAsyncFactory = () => Task.FromResult(mAuthLink.FirebaseToken)
                      });

                await mAuthProvider.SendEmailVerificationAsync(mAuthLink.FirebaseToken);

                return true;
            }
            catch
            {
                return false;
            }
        }
    }