I did online, didnt see anything that looks audioish, but one of them has a triangle that might be it.
I just looked at the pinout, it looks as though the sim 800 is uncommitted, its pins are brought out to the headers, so are not connected up to the processor, and it looks like theres a power amp in there as 2 of the terminals are marked spk.
Cool might have to order one to play with.
Though I did have trouble getting lolin's webserver code to work for the esp32, that said the chip supports the easier to use esp8266's webserver code too, I tried it.