PHP Web Shells Question 2

Sorry this is going to be a few questions in one but to start I figured out how to use Burp suite but only when using the “Open Browser” button. It does not work with Firefox. Is that a bug or a feature? Second, I think I follow all the directions. I download WhiteWinterWolf’s PHP Web Shell from the link provided but it comes with LICENSE, READEME.md, passhash.sh, screenshot.png, and webshell.php. I assume I am only supposed to use webshell.php. After downloading I login and go to the Vendors page. I click add Vendor make my Vendor Name “Apples”. Choose file “webshell.php”. Turn on Burp Suite Intercept. Hit save. On line 29 I change “Content-Type: application/x-php” to “Content-Type: image/gif” . Hit forward twice. Turn off intercept.

I get a picture like this
Apples Capture.

Then I try to go to the /images/vendor/connect.php and it says this
Not Found Capture.

So what am I doing wrong?

Thanks for the help in advance!

Hey past me, its future me. Obviously you cant find the image connect.php because you didn’t name your php file that. Good try though and your def gonna improve. Future you knows it.