KX-TGM430 won't import phonebook entries from iPhone

I'm trying to transfer (copy) the phonebook from an iPhone 6 (software version 12.4.1) to a Panasonic KX-TGM430B 'Link 2 Cell' DECT6 cordless home phone. The Panasonic 'KX' phone and the cell phone are correctly linked, but when I follow the instructions, I get an error-message on the KX phone. If I try to use the 'Auto' import function, I get a "Zero Item completed" message; if I try to use the 'manual' import option, the response I get is "use the cell to transfer phone book". Of course, I have no idea how to do that...

To anyone who can shed some light on this problem - Please Help, and Thank You!