I am new to using Burp Suite. I am trying to learn how to use it with Mutillidae and DVWA. Whenever I right-click on any particular application the "Actively scan this branch/host" and "Passively scan this branch/host" appears disabled. Also, when the "Scanner" tab appears to be disabled. Can anyone tell me the reason why this happens? Does the preset payload being empty have to do anything with this?