The DXP2800 does not have an integrated Wi-Fi module. The DXP480T Plus Ugreen NASync DXP480T Plus (0 TB) has built-in Wi-Fi. You are most likely to have success with a Wi-Fi dongle with an Ugreen AX1800 USB Wi-Fi adapter Ugreen AX1800 Dual-Band Wireless Adapter Wi-Fi 6 (USB) . For me, I have removed Ugreen's own UGOS and installed Linux on it myself. I also use a Wi-Fi adapter on the device.

The NAS has no WIFI, a USB port for backup is available. Unfortunately, I cannot say whether a WIFI dongle will work.

The purpose of a NAS is to have a networked data server, especially as this model has a 2.5 Giga RJ45 socket, but a quick Google search will tell us:

Officially, UGREEN NASync NAS, including the DXP2800, do not support direct Wi-Fi connection and require an Ethernet cable. However, according to user feedback, some Wi-Fi dongles (such as the UGreen AX1800 model) connected via USB can work immediately without configuration. Official recommendation: Use an Ethernet cable for data stability. Alternative tested: A USB-A WiFi dongle plugged into a USB port may be recognised, but this is not guaranteed for all models. Stable solution: For a wireless connection, an Ethernet-to-WiFi adapter (or WiFi bridge) plugged into the NAS's LAN port is a reliable solution if you can't use an Ethernet cable.