Strange though, I'm just now looking at where it said the error was, and it was two lines below where the error actually was; it showed void printResult(HUSKYLENSResult result);, but the error was really where you said it was, HardwareSerial mySerial(2)// RX, TX.
I just found out that I have another problem, though. It isn't an error in the program; it's just that for some reason the serial monitor isn't displaying the Huskylens's output. I first thought that it was because I'm trying to display it on a Google sheet, but I opened that up too, and there's nothing showing up. The project goal is to get the Huskylens to track a soccer ball for goalie training (I'm using a small object to start off with; it can't track fast things), and there are 2 push-buttons that input if the goalie has blocked the ball or not. It displayed the data on the serial monitor just fine when I used the Mega board and the starter code with the modifications at the bottom for the push-button, but when I added the GSheet32 thing and used the ESP32, I had to modify the code into what you see above, and now the serial monitor is continuously printing out dashes every second on the same line, and the Google sheet is doing nothing (I have the Apps Script written, and the code thingy for it is on line 2). Do you know what I did wrong?