Nikon D500 - Manual (Page 74)

74 Menu Guide
When AF-S is selected for viewfinder photography, this option
controls whether photographs can be taken only when the
camera is in focus (focus priority) or whenever the shutter-release
button is pressed (release priority).
Regardless of the option selected, if the in-focus indicator ( I) is
displayed when AF-S is selected for autofocus mode, focus will
lock while the shutter-release button is pressed halfway. Focus
lock continues until the shutter is released.
a2: AF-S Priority Selection
G button
➜ A Custom Settings menu
Option Description
G
Release
Photos can be taken whenever the shutter-release
button is pressed.
F
Focus
Photos can only be taken when the in-focus indicator
(
I) is displayed.