UPDATE

wp-content/themes/upstudy/single.php

@@ -0,0 +1,43 @@
+<?php
+/**
+ * The template for displaying all single posts
+ *
+ * @link https://developer.wordpress.org/themes/basics/template-hierarchy/#single-post
+ *
+ * @package Upstudy
+ */
+
+if ( 'sfwd-courses' === get_post_type() ) :
+	get_template_part( 'learndash/tpl-part/single/content', 'sfwd-courses' );
+	return;
+elseif( 'course' === get_post_type() && class_exists('Sensei_Main' ) ) :
+	get_template_part( 'sensei/tpl-part/single/single');
+	return;
+elseif( 'course' === get_post_type() && class_exists('LifterLMS' ) ) :
+	get_template_part( 'lifterlms/tpl-part/single/single');
+	return;
+elseif( is_singular( upstudy_header_footer_blank_single_post_array() ) ) :
+	get_template_part( 'template-parts/single', 'header-blank' ); 
+	return;
+endif;
+
+get_header();
+
+$single_layout = apply_filters( 'upstudy_single_sidebar_layout', Upstudy::setting( 'blog_single_sidebar' ) );
+echo '<div class="tpc-site-content-inner' . esc_attr( apply_filters( 'upstudy_container_class', ' upstudy-container' ) ) . '">';
+	do_action( 'upstudy_before_content' );
+
+	echo '<div id="primary" class="content-area ' . esc_attr( apply_filters( 'upstudy_content_area_class', 'upstudy-col-lg-9' ) ) . '">';
+		echo '<main id="main" class="site-main tpc-post-details-page">';
+				get_template_part( 'template-parts/single', 'post' );
+		echo '</main>';
+	echo '</div>';
+	
+	if ( 'no-sidebar' !== $single_layout ) :
+		get_sidebar();
+	endif;
+	
+	do_action( 'upstudy_after_content' );
+echo '</div>';
+
+get_footer();