Amazon.com : NEEWER MB-N11 Replacement Vertical Battery Grip with 2.4G Control, Compatible with Nikon Z6 II & Z7 II Camera and EN-EL15c/ EN-EL15b/ EN-EL15a/ EN-EL15 Battery (Batteries Not Included) : Electronics
HOW TO: Nikon Z6 Battery Door Replacement - YouTube
MB-N10 Battery Grip for Nikon Z5 Z6 Z7 Camera Grip - AliExpress