As an administrator you can specify in the settings for which working time types the employees have to submit a request.
This way you can easily control what your employees can record without consultation and what they can't. For example, you can specify that for vacation a request is necessary.
In order to do this, go to the "Administration / Working time types" menu. Click on the edit symbol of the working time type concerned and choose "Edit working time type". You have now the option to define that a request is necessary. Don't forget to save your preferred settings.
From now on employees have to request leave.