I figured out the issue.... at least I figured it out for me and I think this will work for most others.
Just like others, I tried http://localhost
and I tried the local IP...nothing worked. I even created a virtual host with a unique name... it didn't work either. So I decided to let last pass create a password and I opened it to see what lastpass used for the URL. That's how I found out that it was quite simple actually...
If you have a localhost, hopefully you have directories for your work. All I had to do was add http://localhost/Directory
under the "Do Nothing" Category, and it never popped up again. Also, this wasn't just for the index.php file. It also worked for files and classes inside my code that required password validation or password resets. It worked in every case. The only draw back is that you have to add every directory... or you could simply add a master folder in your localhost directory and that would work.
and not only did the index.php file work, but every think inside like password resets and and password verification for secured areas.... everything inside was exempt.
I hope if works for you too... good luck!!