Check below steps in explanation for Task
Explanation:
To add the network interface of a virtual machine named VM1 to an application security group named ASG1, you can follow these steps:
In the Azure portal, search for and select the virtual machine named VM1.
In the left pane, select Networking.
In the Networking pane, select the network interface that you want to add to the application security group named ASG1.
In the network interface pane, select Application security groups.
In the Application security groups pane, select Add.
In the Add application security group pane, select the application security group named ASG1.
Select Save.
You can find more information on this topic in the following Microsoft documentation: Add a network interface to an application security group using the Azure portal.