Once you have your CustomKeys.txt file, place it in the following directory: Custom Hotkeys - Warcraft III: Reforged Forums

Fully personalized configurations using a CustomKeys.txt file or third-party tools to bind specific abilities to your preferred keys (like mapping all hero spells to QWER). Where to Download and Install Custom Hotkeys

If you want advanced setups like the popular QWER or "Improved" layouts, you will need a CustomKeys.txt file.