To submit your score you have to attach an image proof of your score. Do not submit fake screen shots as they will be deleted and you might get banned.
How to create a screen shot?
It is very easy, just follow these instructions. Press the ‘Print Screen’ button on your keyboard which is often next to F12 key (Mac users press: Command + Shift + 3), at the right time when the game screen shows your score. Then open up any image editing software (MS Paint, Gimp, Adobe Photoshop, etc.), create a new document and paste (Windows: press CTRL + V) (Mac: press Command + V) your screen shot. Save the picture & upload it.