WP Responsive Menuの設定Content After Elementに以下のHTMLを挿入 <div class="wp-block-bogo-language-switcher"> <ul class="bogo-language-switcher"> <li style="margin: 1em 0.5em;" class="en-US en first"><span class="bogoflags bogoflags-us"></span> <span class="bogo-language-name"></span></li></ul></div>