Can you find the key move?

Let's see if black has a good way to prevent

Black can try

So, it seems that plan doesn't quite work. However, white has another way to deliver mate:

I think that this is not

but

With the first move being

Analyzing all of black options: After this move, black cannot play

bacause in these cases

One possibility for black is the move

In this case, white cannot play

but has the option to play

Looking at the other possible first moves for black:

Leaving just