How can COTS gateway get the spectrum of LoRa?

I have read a lot of relevant literature, it seems that SDR equipment such as USRP, hackrf series can directly obtain the physical spectrum of the received signal.

How to use the general commercial gateway to do So? For example, how can the gateway with sx1302 module obtain the spectrum.

I’ve heard that spectrum analyzer can be used. I haven’t used it before, so I don’t know how to operate it and its feasibility

You can use dvb-t2 stick with a R820T2 chip