To add Slack as a notification channel, click the Gear icon > Organization Settings > Tools & Integrations. Click on Slack.
Select the Slack channel you’d like to use from the drop down menu, and click Connect. This integration will send all contact messages through to your Slack channel, and you can choose to have Agent responses pushed to Slack as well. The notification in Slack will also include a link to the Conversation in Textline, enabling you to easily access and respond to the message.
Please note that you are not able to respond to a message directly through Slack - you will need to respond to the Conversation through your Textline Dashboard.
Watch the tutorial video on Slack Integration here.