The basic class structure for any Burp Suite extension is in the following code, which is provided by PortSwigger:

package burp; 
 
public class BurpExtender implements IBurpExtender{ 
    public void registerExtenderCallbacks (IBurpExtenderCallbacks callbacks){ 
        // your extension code here 
    } 
} 

This is basically the class definition that is used to create all of Burp Suite's extensions. Now, let's start to modify the code.