Application Loader Troubles

I’m just about finished with setting things up for the App Store. However, I am having a difficult time using the Application Loader in Xcode. It asks for my Apple Id and password, yet when I enter it the program will not accept it and sign me in. Has anyone else experienced this and if so what was your work-around? I’m lost.

Application Loader is a little antiquated. You need to create an app-specific password for Application Loader. See https://support.apple.com/en-gb/HT204397

Thank you Gavin.