It is important and mandatory to add an employee to a team, as a team is always linked to a schedule-layer. Otherwise, an employee cannot be scheduled on a schedule-layer.
Click on the L1NDA-logo on the top left and click on Staff;
Click on the name of the employee;
Click on the square-icon with a pencil (edit-icon);
Select in step 1 the team(s) that this employee work in, for example Kitchen.
In case an employee works in multiple teams, you can hold "Ctrl" or "Command" button and click on multiple teams.
Go to step 2.
Do not forget to 'save' these changes!