Hello Nipun
One of the advantages of using FlexVPN is that it uses Smart Defaults. These are pre-defined settings that are automatically set to default values based on general best practices. These configuration parameters don’t need to be configured by you, and this is one of the benefits of FlexVPN.
One of those parameters is the IPSec transform set. FlexVPN uses specific smart defaults for that, so you don’t have to configure it. All of these smart defaults are detailed in the following lesson:
I hope this has been helpful!
Laz