If you receive the error message "Login failed - The entered access data is incorrect" when logging in to the apps, even though the user was created correctly and the access data is also correct, it may be because the REST API of Shopware is not working in your shop.
You can check this by trying to log in to
www.my-shop.com/api/version
with the corresponding username and REST API key. If you do not get past entering the access data, you know that the problem lies within the REST API. In this case, please contact your server administrator.
You can find the API key in your Shopware backend in the corresponding user account.