Where to find the activation code?

firstly you have to clear your question that what type of code you want, for antivirus you find your code at your card back

In mcafee antivirus

The 12-digit Activation Code can be found in two sections of the web application: users can go to Administration and scroll down to Mobile Apps (the Administration menu can be found in the top right corner of the screen). Once you click Activate next to the driver’s information, you’ll receive the code.

Webroot 

To find your keycode within Webroot SecureAnywhere for Windows PC: Open the main interface. Click My Account. A window opens with your keycode and subscription information.

Trend micro

Enter your Trend Micro Account and Password, and then click the Sign In button.
Deep Security as a Service License

1. Log in to Deep Security as a Service.
2. At the upper-right corner, click your account name.
3. Select Account Details. The pop-up window will show the activation code.

Kaspersky

An activation code is a code that you receive when purchasing a license or subscription for Kaspersky Internet Security. This code is required to activate the application. An activation code is a unique combination of twenty Latin letters and numbers in the form xxxxx-xxxxx-xxxxx-ххххх.