I don't think he needs AT commands for his gps, he just wanted to "check features".
Maybe he just misunderstood the functions. The gui is only to configure the adapter in aspect as:
baud rate needed on serial connector
wifi credentials
forward the serial stream into his local wlan (in STA mode) or as seperate AP
which tcp port to use for telnet access (as "far end" of serial stream)
With one device on the gps side, one can connect via tcp to the configured ip:port and it will behave like a terminal connection via serial; but this will not work like virtual com-port on PC, usable for some software.
I could not yet figure out if this device(s) can be configured/used on both sides so as to provide a real "virtual serial port" on the PC that behaves like the directly connected gps.