How to add WordPress Settings in sidebar widgets

The Text Widget does not parse PHP – it even strips it.

You either could use a widget that is capable of parsing/interpreting PHP, such as the PHP Code Widget, or you could develop your own widget.

Here is a very simple example of how this could look like:

class WPDev172911TitleWidget extends WP_Widget {

    public function widget( $args, $instance ) {

        wp_title();
    }

}