Post /login just fail

when i am post /login, just fail……
use Raspberry Pi(debian) / php7.3-fpm/ nextcloud-18.0.2

this is my log:
{"reqId":"1nKmdiwZALiD2RScBHy7","level":3,"time":"2020-03-18T17:20:11+00:00","remoteAddr":"192.168.1.113","user":"--","app":"password_policy","method":"POST","url":"/login","message":{"Exception":"RuntimeException","Message":"App class OCA\\Password_Policy\\AppInfo\\Application is not setup via query() but directly","Code":0,"Trace":[{"file":"/var/www/html/nextcloud/apps/password_policy/lib/AppInfo/Application.php","line":40,"function":"__construct","class":"OCP\\AppFramework\\App","type":"->","args":["password_policy"]},{"file":"/var/www/html/nextcloud/apps/password_policy/appinfo/app.php","line":23,"function":"__construct","class":"OCA\\Password_Policy\\AppInfo\\Application","type":"->","args":[]},{"file":"/var/www/html/nextcloud/lib/private/legacy/app.php","line":266,"args":["/var/www/html/nextcloud/apps/password_policy/appinfo/app.php"],"function":"require_once"},{"file":"/var/www/html/nextcloud/lib/private/legacy/app.php","line":155,"function":"requireAppFile","class":"OC_App","type":"::","args":["password_policy"]},{"file":"/var/www/html/nextcloud/lib/private/legacy/app.php","line":128,"function":"loadApp","class":"OC_App","type":"::","args":["password_policy"]},{"file":"/var/www/html/nextcloud/lib/base.php","line":1005,"function":"loadApps","class":"OC_App","type":"::","args":[]},{"file":"/var/www/html/nextcloud/index.php","line":38,"function":"handleRequest","class":"OC","type":"::","args":[]}],"File":"/var/www/html/nextcloud/lib/public/AppFramework/App.php","Line":80,"CustomMessage":"--"},"userAgent":"Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.132 Safari/537.36","version":"18.0.2.2"}

No idea because of the errors.

But i added today a user and it did not work because the password was trivial/easy.
Can you reset the password and set another password?
Does it work for other users?

I can‘t ,because I just installed and couldn’t complete the first login…