If Shopware is only in maintenance mode, logging in with the apps is possible without any issues. If the server is secured with a password prompt (HTTP Auth) during test operation, the following URLs must be excluded from this:
/api
/media/image
The first URL is already protected with a login by Shopware itself and is used for the communication of the apps with the Pickware POS or Pickware WMS extension. The second URL must be excluded from authentication so that the product images can be displayed in the apps.
To exclude the mentioned URLs from the password prompt, please contact your agency or directly your hoster so that they can make the changes.