Reset the Launchpad to fix the ordering in macOS Catalina When I was using Yosemite in my old mac, I can simply use defaults write com.apple.dock ResetLaunchPad -bool true; killall Dock to fix the ordering of apps but it is not working in macOS Catalina 10.15

Now I have only the pre-installed apps like App Store, Notes, Music etc. in my launchpad. 

What should I do now?
Try Launchpad Manager. It’s the only tool that I’m aware of that will allow you to edit/control the Launchpad.