Laravel访问出错错误信息：`Warning require(vendorautoload.php) failed to open stream No such file or dire

Warning: require(/opt/project/erp_api/public/../vendor/autoload.php): failed to open stream: No such file or directory in /opt/project/erp_api/public/index.php on line 24

Fatal error: require(): Failed opening required ‘/opt/project/erp_api/public/../vendor/autoload.php’ (include_path=’.:’) in /opt/project/erp_api/public/index.php on line 24

原因：网站根目录下缺少vendor这个存放laraver依赖包的目录
解决方法：使用composer install进行安装
（没有安装过的情况下，以前安装过的话使用：composer update）