Final answer:
To go to the next line in Slack without sending the message, use the Shift + Enter (or Shift + Return on Mac) keyboard shortcut.
Step-by-step explanation:
On the Slack messaging platform, if you want to go to the next line without sending your message, you can use the following keyboard shortcut: press Shift + Enter (or Shift + Return on a Mac). This will allow you to start a new line in the same message rather than triggering the send action, which happens when you press Enter or Return on its own.
As a reminder, this works in the Slack desktop app, the web client, and the mobile app as well. So, whether you're writing longer paragraphs, creating lists, or just want to structure your message with better readability, using Shift + Enter can be extremely helpful.