When sending an Update via Slack, you will see all of your public channels by default. In order to send an Update to a private channel, follow the steps below:
To get started, you will need to add the Visible app to the specific Slack channel as shown below:
From here, you will be able to see the private channel in Visible. As a note, you may need to refresh your browser.
Please let us know if you have any additional questions!