In some photographs of the Moon, there are bright spots in the dark part of the Moon. Some flat-earthers believe that these are ‘stars’, and the Moon is actually transparent.
These are in fact image noise, not stars.
There is often noticeable noise in images taken by camera. These generally occurs due to high sensitivity (ISO) settings, long exposure, or dark scenes.
In these pictures of the Moon, the noise is the salt-and-pepper type. It results in dark pixels in bright regions and bright pixels in dark regions. These are often very perceptible on very long exposure images. Noise is just noise. The bright spots are only seen on the pictures, but not part of the real object.
The picture on the right was taken with lens cap on, so that light cannot reach the sensor, and anything in the image is just noise. It was taken on ISO 3200 and 30 seconds long exposure. It almost perfectly reproduces the noise seen on the image of the Moon on the left. Astro-photographers sometimes exercise a technique called the dark-frame subtraction in order to minimize the noise.
In short: The bright spots on the dark part of the Moon are not stars. They are just noise and not part of the real object. Light from stars cannot pass through the Moon. And finally, the Moon is not transparent.