The work times of several staff members for one and the same event can be copied into an invoice directly if corresponding shifts were created beforehand.
Open the event.
If there are any open work times, right-click on Invoice > Edit staff times.
Confirm the details by ticking the "OK" column and save.
Right-click on Invoice > Confirm staff times.
Double-click or left-click and Confirm to select the times you want.
Decide whether you want to apply the price of the staff item or the staff member.
Save your input by clicking on the icon in the top left-hand corner of the input window.