How to write the Alligator teeth in Amibroker?

The Alligator’s Teeth, the “Red” line, is an 8-period Smoothed Moving Average, moved by 5 bars into the future;

@ali.ghfath I would first suggest you review this forum post,
How to ask a good question

But I assume you are referring to the old Bill Williams "alligator" stuff and you've read a couple of his books from the mid-1990's (is he still alive and selling courses as opposed to actually trading?)

It is all coded into afl in the User Library,