public bool SaveContactData(string firstName,string lastName, string identifierSource, string email,string phoneNumber, string language, string userAgent)
        {
            try
            {
                var contactReference = GetIdentifiedContactReference(identifierSource, email);

                using (var client = SitecoreXConnectClientConfiguration.GetClient())
                {
                    var contact = client.Get(contactReference, new ContactExpandOptions(CollectionModel.FacetKeys.PersonalInformation, CollectionModel.FacetKeys.EmailAddressList, PhoneNumberList.DefaultFacetKey));

                   //CONTACT IS COMING NULL 



                }
                return true;
            }
            catch (Exception ex)
            {
                Log.Error("Error saving data to profile", ex, this);
                return false;
            }
        }

 private IdentifiedContactReference GetIdentifiedContactReference(string identifierSource, string identifier)
        {
            if (Tracker.Enabled && !Tracker.Current.IsActive)
            {
                Tracker.StartTracking();
            }

            if (Tracker.Current?.Contact == null)
            {
                Log.Warn("Tracker.Current?.Contact == null", this);
                return null;
            }

            if (Tracker.Current.Contact.IsNew)
            {
                Tracker.Current.Contact.ContactSaveMode = ContactSaveMode.AlwaysSave;
                _contactManager.SaveContactToCollectionDb(Tracker.Current.Contact);
                IdentifyContact(identifierSource, identifier);
                return new IdentifiedContactReference(identifierSource, identifier);

            }

            var id = Tracker.Current.Contact.Identifiers.FirstOrDefault();
            return Tracker.Current.Contact.IsNew || Tracker.Current.Contact.Identifiers.Count == 0
                ? new IdentifiedContactReference(identifierSource, identifier)
                : new IdentifiedContactReference(id?.Source, id?.Identifier);
        }

public bool SaveContactData(string firstName, string lastName, string identifierSource, string email, string phoneNumber, string language, string userAgent)
{
    try
    {
        var contactReference = GetIdentifiedContactReference(identifierSource, email);

        using (var client = SitecoreXConnectClientConfiguration.GetClient())
        {
            var contact = client.Get(contactReference, new ContactExpandOptions(CollectionModel.FacetKeys.PersonalInformation, CollectionModel.FacetKeys.EmailAddressList, PhoneNumberList.DefaultFacetKey));

            //CONTACT IS COMING NULL
        }
        return true;
    }
    catch (Exception ex)
    {
        Log.Error("Error saving data to profile", ex, this);
        return false;
    }
}

private IdentifiedContactReference GetIdentifiedContactReference(string identifierSource, string identifier)
{
    if (Tracker.Enabled && !Tracker.Current.IsActive)
    {
        Tracker.StartTracking();
    }

    if (Tracker.Current?.Contact == null)
    {
        Log.Warn("Tracker.Current?.Contact == null", this);
        return null;
    }

    if (Tracker.Current.Contact.IsNew)
    {
        Tracker.Current.Contact.ContactSaveMode = ContactSaveMode.AlwaysSave;
        _contactManager.SaveContactToCollectionDb(Tracker.Current.Contact);
        IdentifyContact(identifierSource, identifier);
        return new IdentifiedContactReference(identifierSource, identifier);

    }

    var id = Tracker.Current.Contact.Identifiers.FirstOrDefault();
    return Tracker.Current.Contact.IsNew || Tracker.Current.Contact.Identifiers.Count == 0
        ? new IdentifiedContactReference(identifierSource, identifier)
        : new IdentifiedContactReference(id?.Source, id?.Identifier);
}