If you want to add it into the config.xml then code looks like this:
<edit-config target="NSCameraUsageDescription" file="*-Info.plist" mode="merge">
<string>need camera access to take pictures</string>
</edit-config>
<edit-config target="NSPhotoLibraryUsageDescription" file="*-Info.plist" mode="merge">
<string>need photo library access to get pictures from there</string>
</edit-config>
<edit-config target="NSLocationWhenInUseUsageDescription" file="*-Info.plist" mode="merge">
<string>need location access to find things nearby</string>
</edit-config>
<edit-config target="NSPhotoLibraryAddUsageDescription" file="*-Info.plist" mode="merge">
<string>need photo library access to save pictures there</string>
</edit-config>
and if you prefer going into the -Info.plist file then:
<key>NSCameraUsageDescription</key>
<string>need camera access to take pictures</string>
<key>NSPhotoLibraryUsageDescription</key>
<string>need photo library access to get pictures from there</string>
<key>NSLocationWhenInUseUsageDescription</key>
<string>need location access to find things nearby</string>
<key>NSPhotoLibraryAddUsageDescription</key>
<string>need photo library access to save pictures there</string>