function llms_merge_code_button( $target = 'content', $echo = true, $codes = array() ) {

	$screen = get_current_screen();

	if ( ! $codes && $screen && isset( $screen->post_type ) ) {

		switch ( $screen->post_type ) {

			case 'llms_certificate':
				$codes = llms_get_certificate_merge_codes();
				break;

			case 'llms_email':
				$codes = array(
					'{site_title}'    => __( 'Website Title', 'lifterlms' ),
					'{site_url}'      => __( 'Website URL', 'lifterlms' ),
					'{email_address}' => __( 'Student Email Address', 'lifterlms' ),
					'{user_login}'    => __( 'Student Username', 'lifterlms' ),
					'{first_name}'    => __( 'Student First Name', 'lifterlms' ),
					'{last_name}'     => __( 'Student Last Name', 'lifterlms' ),
					'{current_date}'  => __( 'Current Date', 'lifterlms' ),
				);
				break;

			default:
				$codes = array();

		}
	}

	/**
	 * Filters the list of available merge codes in the specified context.
	 *
	 * @since Unknown
	 *
	 * @param array[]        $codes  Associative array of merge codes where the array key is the merge code and the array value is a name / description of the merge code.
	 * @param WP_Screen|null $screen The screen object from `get_current_screen().
	 * @param string         $target Target to add the merge code to. Accepts the ID of a tinymce editor or a DOM ID (#element-id).
	 */
	$codes = apply_filters( 'llms_merge_codes_for_button', $codes, $screen, $target );

	$html = '';
	if ( $codes ) {
		ob_start();
		include LLMS_PLUGIN_DIR . 'includes/admin/views/merge-code-button.php';
		$html = ob_get_clean();
	}

	if ( $echo ) {
		echo $html;
	}

	return $html;

}