Tap the screen once to get back to the player menu (either by using an USB-Mouse or the remote for when using the viewneo 4K SignageBox). A lock appears in the upper right corner. Tap on the lock. If you activated the kiosk mode you will be asked for the PIN. Otherwise you will get to the player menu directly.
Insert your pin if applicable. You will get to the menu if the PIN is correct. After three false attempts to insert the PIN, the access is blocked for five minutes. In case you forget your PIN, you can use a super-PIN to access the menu. The super-PIN can be found in your viewneo account under the information about the device.