Hi again,
You can install this little plugin: https://wordpress.org/plugins/custom-css-js/ and then add custom JavaScript:
jQuery(document).ready(function() {
setTimeout(function() {
MYMAP[1].map.setOptions( {
styles: [{
featureType: "administrative.country",
elementType: "labels",
stylers: [
{ visibility: "off" }
]
}]
});
}, 500);
});
Hope that helps.
Best