public override async Task Run()
        {
            var channel = ActivityUI.ChannelSelector.Value;
            var message = ActivityUI.MessageSource.TextValue;
            var success = await _slackIntegration.PostMessageToChat(AuthorizationToken.Token, channel, message).ConfigureAwait(false);

            if (!success)
            {
                throw new ActivityExecutionException("Failed to post message to Slack");
            }
        }
        public override async Task Run()
        {
            var actionChannelId = GetControl <DropDownList>("Selected_Slack_Channel")?.Value;

            if (string.IsNullOrEmpty(actionChannelId))
            {
                RaiseError("No selected channelId found in activity.");
            }

            var messageField = GetControl <TextSource>("Select_Message_Field");

            try
            {
                await _slackIntegration.PostMessageToChat(AuthorizationToken.Token,
                                                          actionChannelId, StripHTML(messageField.TextValue));
            }
            catch (AuthorizationTokenExpiredOrInvalidException)
            {
                RaiseInvalidTokenError();
            }
            Success();
        }