If there is not a pot on the face of the gyro, then it's going to be located inside the Tx. If it's not there, then I doubt it has one. Not sure what heli you have so can't be any more specific.
sounds like an old e-flite cx2 if so it is fitted with a eflh1024 4in1 control unit which has two pots one "gain trimmer pot" for gyro and the other "main motor proportional mix trimmer pot" for balancing motor output.
The manual is available on line or you can pm me and i can supply a copy.
E-flite cx-2 in original condition.
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