The add-in allows 3 way to set it up

1. From the workflow
2. From the user info list
3. From the manager of department list

From the workflow

1. Go to the general configuration page. Then select From workflow in the Get Manager dropdown
2. Go to the workflow page, then click an icon of manager step
3. Set the Select User checkbox is No
4. In the Assign To dropdown, select user who is manager

From the user info list

1. Go to the general configuration page. Then select From user info list in the Get Manager dropdown
2. Go to the user info list by click Settings -> User info list in the configuration section
3. Then add the manager for each employee

From the manager of department list

1. Go to the general configuration page. Then select From manager of department list in the Get Manager dropdown
2. Go to the Manager of Department list by click Settings -> Manager of Department in the configuration section
3. Then add the manager for each department