Select the Settings section.
Tap VPN & Device Management.
Tap Add VPN Configuration.
In the section Subscriptions look for a domain of IKEv2 VPN, Username and Password VPN.
Follow these steps:
Connect to IKEv2 VPN server on iOS (iPhone, iPad).
IKEv2 VPN connection successfully established.
In the future, you can connect to IKEv2 VPN in the Settings section.
Disconnect from IKEv2 VPN on iOS if needed.