If you have added extra liquids afterwards, you can enter using the extra parts option. This can be updated until the car is reported ready!
The "extra parts" button is at the top right of the work order, as shown below.
When you open the extra parts function, the extra parts list will appear. By filling this list the extra parts added will be stored and processed.
If you want to see what has been added afterwards, you can open the extra parts in the work order.
If the mechanic uses the extra parts function, the status of the work order will not change. Also, the service advisor does not need to give "Customer OK".