Shabana, I think you are right.
When we ask, "What does the Protagonist need," it's that need which exists at the very beginning which becomes ignited by some event…
Shabana, I think you are right. Whether there is a specific event or moment which presages the ending ... or it's more of a generalized state of the Protagonist's being or situation ... as Ovid wrote, "The seeds of change lie within." They are there at the beginning.
When we ask, "What does the Protagonist need," it's that need which exists at the very beginning which becomes ignited by some event (Inciting Incident / Call to Adventure), then emerges from the characters inner self, energizing and driving them ahead toward the ending when their need is actualized.
That's an example of the unity arc which is the most common narrative archetype. There are other types of stories. But even there, it's almost certain that the seeds of the ending are present at the very beginning.
Which is to say ... you and I are having an agreement!