Sorry there was a bug. No need to enter anything.
/wp-content/plugins/skip-to/js/SkipToInit.js can be simply empty. Just the JS need to be loaded.
By Default it will show only onFocus.
Once installed, activate and start tabbing from address bar. You should be able to see the Floating Menu link.
If you want to always show the floating SkipTo link, change /wp-content/plugins/skip-to/js/SkipToInit.js . Change onFocus to onLoad.
Can also change in Settings.