Can not access stats no matter what I try

[BigWhiteDog]

I'm trying to access stats for the first time. I go to www.domainnamedotcom/pleask-stats and a log in window appears. I first put in the domain username and pw and got a 403 error and could not get the log in window back without closing the browser and clearing cookies. I then set up a new user for the protected directory and tried that log in info and get the same thing.
I searched for this problem here and tried the few answers I found and nothing works. I do not now how to use command line so if a solution involves using it then I will need step-by-step instructions. Thanks in advance!