To view or add notes, click the avatar of the person from the main canvas:

When their profile loads, there most recent notes will be displayed in Intercom as pulled from SalesLoft. To add a new note, click Add Note

Then you can add a Subject and Content to the note, and when ready, click Add Note

If successful, you will receive positive feedback:

The details of this new note, and other notes, are available in the profile view or in the Notes section of the SalesLoft person: