Hi Llian,
Labels received an overhaul in version 19 so they behave a little differently.
Now you can either:
• Activate the label tool; pick the appropriate label type or favorite; then click on the element to label it.
OR
• Select multiple elements you wish to label; click the "Label Selected Elements" button* (or go to Document > Label Selected Elements*).
*USA version Standard Profile 20 only:
- Label Selected Elements button is on the standard toolbar to the left of the eyedropper.
- Menu = Document > Label Selected Elements
The INT version Standard Profile 20:
- Menu item is under Document > Annotation > Label Selected Elements
Best regards,