Warning: require(vendor/autoload.php): Failed to open stream: No such file or directory in /home/.sites/884/site2951/web/_mailer/get_oauth_token.php on line 18

Fatal error: Uncaught Error: Failed opening required 'vendor/autoload.php' (include_path='.:/opt/alt/php84/usr/share/pear:/opt/alt/php84/usr/share/php:/usr/share/pear:/usr/share/php') in /home/.sites/884/site2951/web/_mailer/get_oauth_token.php:18
Stack trace:
#0 {main}
  thrown in /home/.sites/884/site2951/web/_mailer/get_oauth_token.php on line 18