Wrong password on Windows-Client

Hi all. I have installed an owncloudserver and everything works fine with webinterface. But when I try to connect via windows desktop client it says username/password are wrong. I have tried Admin account and an useraccount. Same error message.

Expected behaviour

establish connection by using desktopclient

Actual behaviour

it says wrong username/password

Steps to reproduce

  1. click “add new account”
  2. type server adress
  3. try to type username/password…

Server configuration

Operating system: Plesk Obsidian v18.0.48_build1800221104.03 os_Ubuntu 20.04

Web server: apache

Database: mariadb

PHP version: 7.4.33

ownCloud version: lastest

Storage backend (external storage): ?

Client configuration

Client version: 3.0.0.3215

Operating system: Win 10 21H2

OS language: German

Installation path of client: default

Is Webdav needed for the login?