How to fix Wordpress Error wp-settings.php line 173

Followed this wordpress tutorial, stuck on step 3 because I get this error warning everytime I try to access my droplet’s IP/domain

Warning: require(/var/www/html/wp-includes/class-wp-theme-json-schema.php): Failed to open stream: No such file or directory in /var/www/html/wp-settings.php on line 173

Fatal error: Uncaught Error: Failed opening required ‘/var/www/html/wp-includes/class-wp-theme-json-schema.php’ (include_path=‘.:/usr/share/php’) in /var/www/html/wp-settings.php:173 Stack trace: #0 /var/www/html/wp-config.php(96): require_once() #1 /var/www/html/wp-load.php(50): require_once(‘…’) #2 /var/www/html/wp-blog-header.php(13): require_once(‘…’) #3 /var/www/html/index.php(17): require(‘…’) #4 {main} thrown in /var/www/html/wp-settings.php on line 173`