i don’t know if you find which pins, but try PA_9 as TX and PA_10 as RX, or maybe the inverse, i don’t remember, have a look on the datasheet, it worked fine for me. You can also define the pins you want to use by declaring them as following
Serial pc(PE_1, PE_0); the first one is TX the second is RX, and then set up your baud rate by pc.baud(115200);
