Verifying when add VPN profile configuration

Hi, I am developing a VPN which create a Packet Tunnel Provider.

When I use NETunnelProviderManager to add an Open VPN profile, system throw a popup require verify Passcode or Touch Id for granting permission to continue.

BUT I never see a Face Id popup though my app has Privacy - Face ID Usage Description.

Can you help me explain it?

Verifying when add VPN profile configuration
 
 
Q