Thanks viking65 for this informations !

But is it really necessary to go through an online site to insert an image? Isn't there a simpler method, directly from the forum, like for youtube videos for example?
Maybe the staff can tell us! and could also answer my request by putting these techniques in the FAQ, it would help everyone, and would be more easily accessible!

The only technique I knew was the one for insert a youtube video!

The staff still has to explain the eighth icon, and answer my suggestion 3) concerning the conversion of rebate points, a simple click on a button would be much easier and more practical!