macOS remove Ukelele custom keyboard layout

Question

I like to remove the input source

I have installed the custom keyboard layout from Ukelele. And it cannot be uninstalled from Ukelele anymore. This input source may be installed through a dmg file generated by Ukelele.

All other Ukelele input source can be install and uninstall without any issue.

This is not the setting in ~/Library/Preferences/com.apple.HIToolbox.plist