OK I have found the good solution but I am totally perplex
My object is on the ground
The curve is on the ground

The axis on the left corner are the default current axis of the curve + object
I don't find any coherence between them and the good result axis found for have the object sliding perpendicular on the curve on the good position!
I must make many try / error for find good result, and I am not satisfy of that
I must miss something for an easy find!
(always with the same previous file uploaded)