Nikabot integrates with Slack and automatically synchronizes the list of teammates with those in your Slack workspace. If you're an admin in Slack, you can add and remove team members from your Slack workspace and the changes will be reflected in Nikabot.
See how to manage team members in Slack.
If you're looking to activate or deactivate Nikabot tracking for an existing user in your team, go to the Team Members page, tick the box on the left column, click the Edit button, and toggle Time Tracking On.
Or use the toggle button on the Tracking column.