Warning: require_once(/var/www/html/wp-content/themes/news-sync/vendor/autoload.php): Failed to open stream: No such file or directory in /var/www/html/wp-content/themes/news-sync/inc/payment-functions.php on line 8

Fatal error: Uncaught Error: Failed opening required '/var/www/html/wp-content/themes/news-sync/vendor/autoload.php' (include_path='.:/usr/local/lib/php') in /var/www/html/wp-content/themes/news-sync/inc/payment-functions.php:8
Stack trace:
#0 /var/www/html/wp-includes/class-wp-hook.php(324): newssync_init_stripe('')
#1 /var/www/html/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters(NULL, Array)
#2 /var/www/html/wp-includes/plugin.php(517): WP_Hook->do_action(Array)
#3 /var/www/html/wp-settings.php(727): do_action('init')
#4 /var/www/html/wp-config.php(179): require_once('/var/www/html/w...')
#5 /var/www/html/wp-load.php(50): require_once('/var/www/html/w...')
#6 /var/www/html/wp-blog-header.php(13): require_once('/var/www/html/w...')
#7 /var/www/html/index.php(17): require('/var/www/html/w...')
#8 {main}
  thrown in /var/www/html/wp-content/themes/news-sync/inc/payment-functions.php on line 8