I have an installation problem.

kami

The installation document says to enter the "composer create-project flarum/flarum. --stability=beta" installation.But composer reports an error when I type this way.

[RuntimeException]
Could not delete /data/wwwroot/XXX/.:

I can't figure out what the problem is. Permission? Group?I've set everything up and found no problems.
Then on a whim, I deleted the middle point. Input: composer create-project flarum/flarum --stability=beta. The installation is complete.
What's the reason?

kami

also
PHP Fatal error: Class UpdateHelper\ComposerPlugin contains 2 abstract methods and must therefore be declared abstract or implement the remaining methods (Composer\Plugin\PluginInterface::deactivate, Composer\Plugin\PluginInterface::uninstall) in /data/wwwroot/103.86.46.182/flarum/vendor/kylekatarnls/update-helper/src/UpdateHelper/ComposerPlugin.php on line 11

Fatal error: Class UpdateHelper\ComposerPlugin contains 2 abstract methods and must therefore be declared abstract or implement the remaining methods (Composer\Plugin\PluginInterface::deactivate, Composer\Plugin\PluginInterface::uninstall) in /data/wwwroot/103.86.46.182/flarum/vendor/kylekatarnls/update-helper/src/UpdateHelper/ComposerPlugin.php on line 11