"5G" (fifth generation) is a designation for a cellular telephone standard. "5GHz" (five gigahertz) is a frequency band used by wifi systems -- it's a newer allocation that supplements the older 2.4GHz frequency band used previously.
No wifi device connects to 5G cell towers. Your phone has a completely different kind of wireless radio hardware from a wifi dongle, card, or router (although your phone might have that one also, if it can connect to wifi in addition to cell towers).
The wifi dongle supplied with the B2 connects to 2.4GHz routers (or dual-band routers on the 2.4GHz band) only. So if your radio station network router is 5GHz-only, the B2 will not connect.