gremlin issues

Hello! Just bought a new gremlin and assembled it and flashed it with beta flight following the old flight test video... And everything was going great until the receiver section. For some reason, it just won't contact or recognize the receiver! It may be the ports or something (First time using...

This is my first post (if I put it in the wrong spot, my apologies) I received the gremlin kit for Christmas, ive built multi rotors before and even helped a friend build his gremlin) to start off im using a DXE radio (the cheap one with no screen) and the spectrum DSMX FPV Racing serial...