I've seen the Simplex algorithm given to students (my own two children!) without an explanation of how it works. It's fairly easy to learn the required steps without knowing how it works. (Many people can drive a car without knowing how an engine works.) I suspect that you,
@aymane , are in this very position. Perhaps your professor is reluctant to give you extra material that will never appear on your exams. It's also possible that your prof doesn't actually know how it works, they might just know how to perform the algorithm themselves!
I very much like that you're interested to know
how it works. IMO this shows that you'll have a good future in maths!
I used to have a good understanding of its functionality but I've forgotten. I suspect it wouldn't take me too long to re-learn it. However I'd recommend that you follow the tips from
@Subhotosh Khan and
@Jomo to see if you can work it out for yourself (as a hobby, since it probably isn't required for your course). If you're stuck then tell us the name of your textbook, and have a go at explaining it yourself.