This plugin is build using CSS only.
You need Javascript to do this. Something like this should work:
( function() {
jQuery( document ).ready( function() {
jQuery( ".fsmfe-wrapper" ).find( "a" ).click( function() {
jQuery( this ).closest( ".fsmfe-wrapper" ).find( ".menu-toggle" ).prop( "checked", false );
} );
} );
}() );