Attain sidebar compatibility with just about any theme when using LifterLMS

lifterlms-sidebar-compatibility.php

<?php // do not paste this line into your functions.php
/**
 * Display lesson and course custom sidebars on the appropriate LifterLMS pages
 *
 * @param  array $sidebars_widgets  array of registered sidebars
 * @return array
 */
function lifterlms_sidebar_compatibility( $sidebars_widgets ) {
	
	// replace the widgets in the primary sidebar with LifterLMS Course sidebar on Course Pages
	if ( is_singular( 'course' ) && array_key_exists( 'llms_course_widgets_side', $sidebars_widgets ) ) {
		// replace "sidebar-1" with your theme's sidebar id
		$sidebars_widgets['sidebar-1'] = $sidebars_widgets['llms_course_widgets_side'];
	}
	// replace the widgets in the primary sidebar with LifterLMS Lesson sidebar on Lesson Pages
	elseif ( is_singular( 'lesson' ) && array_key_exists( 'llms_lesson_widgets_side', $sidebars_widgets ) ) {
		// replace "sidebar-1" with your theme's sidebar id
		  $sidebars_widgets['sidebar-1'] = $sidebars_widgets['llms_lesson_widgets_side']; 
	}

	return $sidebars_widgets;

}
add_filter( 'sidebars_widgets', 'lifterlms_sidebar_compatibility' );