Python code:

import cv2
import numpy
import win32gui, win32ui, win32con
import time
import PIL
import pyautogui

class WindowCapture:

    # properties
    w = 0
    h = 0
    hwnd = None
    cropped_x = 0
    cropped_y = 0
    offset_x = 0
    offset_y = 0

    # constructor
    def __init__(self, window_name):
        # find the handle for the window we want to capture
        self.hwnd = win32gui.FindWindow(None, window_name)
        if not self.hwnd:
            raise Exception('Window not found: {}'.format(window_name))

        # get the window size
        window_rect = win32gui.GetWindowRect(self.hwnd)
        self.w = window_rect[2] - window_rect[0]
        self.h = window_rect[3] - window_rect[1]

        # account for the window border and titlebar and cut them off
        border_pixels = 8
        titlebar_pixels = 30
        self.w = self.w - (border_pixels * 2)
        self.h = self.h - titlebar_pixels - border_pixels
        self.cropped_x = border_pixels
        self.cropped_y = titlebar_pixels

        # set the cropped coordinates offset so we can translate screenshot
        # images into actual screen positions
        self.offset_x = window_rect[0] + self.cropped_x
        self.offset_y = window_rect[1] + self.cropped_y

    def get_screenshot(self):
        bbox = win32gui.GetWindowRect(self.hwnd)
        pil_img = PIL.ImageGrab.grab(bbox)
        open_cv_image = numpy.array(pil_img)
        open_cv_image = open_cv_image[:, :, ::-1].copy() 
        return open_cv_image

wincap = WindowCapture('Farmer Against Potatoes Idle')
needle_img = cv2.imread('./potato-face-2.png', cv2.IMREAD_UNCHANGED)

start_time = time.time()
while(True):
    
    loop_time = time.time()
    duration_time = loop_time - start_time
#     print(f"duration: {duration_time}")
    haystack_img = wincap.get_screenshot()
    result = cv2.matchTemplate(haystack_img, needle_img, cv2.TM_CCOEFF_NORMED)
    threshold = 0.5
    min_val, max_val, min_loc, max_loc = cv2.minMaxLoc(result)
    if max_val >= threshold:
        needle_w = needle_img.shape[1]
        needle_h = needle_img.shape[0]
        top_left = max_loc
        bottom_right = (top_left[0] + needle_w, top_left[1] + needle_h)
        cv2.rectangle(haystack_img, top_left, bottom_right, color=(0, 255, 0), thickness=2, lineType=cv2.LINE_4)
        my_font = cv2.FONT_HERSHEY_SIMPLEX
        if max_val > 0.7:
            my_color = (255, 0, 0)
        else:
            my_color = (0, 255, 0)
        center_point = (top_left[0] + needle_w//2, top_left[1] + needle_h//2)
#         print(f"hit: {center_point} {max_val}")
        my_text = str(max_val)
        cv2.putText(haystack_img, my_text, center_point , my_font, 2, my_color)
        if max_val > 0.7:
            pyautogui.moveTo(center_point)
            pyautogui.click()
            
    cv2.imshow('Result', haystack_img)
#     if (duration_time > 45) or (cv2.waitKey(1) == ord('q')):
    if (cv2.waitKey(1) == ord('q')):
        cv2.destroyAllWindows()
        break