Yes, in most cases you can install a Stages power meter on your Gossamer crankset. Please note, for a time around 2014, FSA used a pinch bolt style interface (Shimano). You need to confirm your crankset is not that type, because a Stages power meter will not fit if so.
Assuming it’s not, then the next step is to determine if your crankset is 386EVO or BB30. If you have a 386EVO, then you can install the Stages Carbon for FSA 386 EVO Power Meter.
If it is BB30, you can install the Stages FSA SL-K BB30 Power Meter.
Please note, these power meters attach a sensor to the inside of the left crank arm. On some bikes, there is not enough room between the left crank arm and the chainstay for the sensor to clear the frame. Therefore, you should make sure you have at least 10 mm of clearance for Stages power meters. Also, please make sure that you don’t have a bottom bracket mounted rear brake (used on some aero and TT bikes). Please refer to the image below.