Welcome welcome @AMIRUL_DEWA_RIZKY to the forum! It is a lovely place where you can share all kinds of stuff (appropriate of course), share bugs, and even get assistance for code! We suggest that you review this topic which shows all essentials of this board! And we suggest you review this topic which shows how to post your code correctly! Thanks!! 
Could it possibly because you are not a subscriber? I think the level Sand Snakes is subscriber only. Correct me if I’m wrong.
Lydia