Go to the All Programs section.
Enter in the search bar: terminal and run Terminal app.
Update all current packages on Ubuntu. You may need to enter a root password.
sudo apt-get update
Run the following command to install IKEv2 VPN.
sudo apt-get install -y strongswan network-manager-strongswan libcharon-extra-plugins
Open connection settings.
Set up a new VPN connection.
Choose IPSec/IKEv2 (strongswan).
In the section Subscriptions look for a domain name for the IKEv2 VPN, and also Username and Password VPN.
Follow the steps below:
Connect to IKEv2 VPN on Ubuntu 21.
IKEv2 VPN connection successfully established.
You can also connect to IKEv2 VPN through the top menu.
Disconnect from VPN network if necessary.