Returning a point by a specific pixel value or range using Google Earth Engine

You can use .selfMask() to remove all zero values, then .sample() your image after adding .pixelLonLat() to retrieve the pixel values.

To convert the pixel values to a list, you can use .aggregate_array('longitude') and .aggregate_array('latitude'), or use .reduceColumns() using whichever reducer you need to provide the results you're looking for (e.g. mean(), minMax(), toList(), etc.)

// These weren't shared in the original question so still to define:
// image - your image of interest
// roi - your region of interest

// Mask zero values, add PixelLonLag, clip to roi
var imgWithPixLonLat = image.selfMask().addBands(ee.Image.pixelLonLat()).clip(roi)

// Pixel longitude values as a list
print(imgWithPixLonLat.sample().aggregate_array('longitude'))

// Mean lon/lat values 
print(imgWithPixLonLat.sample().reduceColumns({reducer: ee.Reducer.mean().repeat(2),
                                         selectors: ['longitude', 'latitude']
}))