In your WordPress website, go to WP-Admin > Opt-in Samurai > 3rd Party Integration
Click Activate button under Aweber Logo
Under the form in bottom, click on the Authorize Access Link
You will be taken to your Aweber account login screen (On Aweber website)
Enter your Aweber login information and click Authorize
You will be taken back to the 3rd Party Integration page in Opt-in Samurai
Hit Save Changes button and you are done!