Register Forum Sidebar

functions.php

if ( ! function_exists( 'my_theme_widgets_init' ) ) :

	/** Function my_theme_widgets_init */
	function my_theme_widgets_init() {
		if ( class_exists( 'bbPress' ) ) {
			register_sidebar(
				array(
					'name'          => esc_html__( 'Forums Sidebar', 'my-theme' ),
					'id'            => 'sidebar-forum',
					'before_widget' => '<aside id="%1$s" class="widget %2$s">',
					'after_widget'  => '</aside>',
					'before_title'  => '<h3 class="widget-title">',
					'after_title'   => '</h3>',
				)
			);
		}
	}
endif;
add_action( 'widgets_init', 'my_theme_widgets_init' );