Using the Enabled property – PB Docs 2017

If the Enabled property is selected, the control is active. For
example, an enabled CommandButton can be clicked, a disabled
CommandButton cannot.

If you want a control to display but be inactive, be sure the
Enabled property is not selected in the General tab page in the
control’s Properties view. For example, a CommandButton might be
active only after the user has selected an option. In this case,
display the CommandButton initially disabled so that it appears grayed
out. Then, when the user selects the option, enable the CommandButton
in a script: