Yes, it works with Ubiquiti PoE+ provided by a switch, as the device supports PoE+ in accordance with IEEE 802.3at (26 watts). It does not require only the supplied power adapter, since the single RJ45 port accepts standard PoE+ power over Ethernet.
The device can also be used as a Wi-Fi router without a SIM card by connecting to a campsite's Internet access via Wi-Fi and then forwarding this to several devices via its own Wi-Fi. This allows you to log on to the campsite with just one access point and connect several devices via the router. The FRITZ!Box 6860 5G supports this function as a WLAN relay to use an existing WLAN network and connect your own devices via it.