Add Empty Option To Countries List

/**

 * In this example we add an empty "Select your country"

 * option at the start of the list of countries in the

 * donation form.

 */

add_action(

	'init',

	function() {

		$fields    = charitable()->donation_fields();

		$field     = $fields->get_field( 'country' );

		$form      = $field->donation_form;

		$countries = array_merge(

			array( '' => 'Select your country' ),

			$form['options']

		);

		$field->set( 'donation_form', 'options', $countries );

		$field->set( 'donation_form', 'default', '' );

	}

);