Linda From Maine wrote:
Has she used that battery previously? If not, a note I found online:
You may have noticed that Panasonic have gone to great lengths to warn
you about the use of counterfeit or third party batteries because of the
risk of fire or explosion within the camera and have introduced a method
of establishing if the inserted battery has the Panasonic safety check
mechanism warning you that “this battery cannot be used” if a nonapproved battery is inserted.
Nikon does the same for their newer models. The non Nikon batteries that worked in my D800 don't work in my Z6. The battery mfgs will catch up.
But I don't believe the explanation. I suspect it is a marketing ploy to sell branded batteries.