Though the primary way of installing Xcode is via MAS (requiring Apple ID login), Xcode can be downloaded from the Apple Developer website without an ADP membership, though you do have to log in to the website with an Apple ID. You don’t have to log into the Mac with an Apple ID though, you can then install and use it on a Mac without an Apple ID (though you will need one inside Xcode to sign apps to get them to run on an iOS device).