SpeedTree to UE4 has no wind after importing

When I import into UE4 I only see this: Screenshot 1 — ImgBB

I do not see any include vertex data option. I do not see any include wind option.

Here is what the official tutorial says I should be seeing when I import the file into UE4: Screenshot 2 — ImgBB

What am I missing?
I am clearly doing something wrong.

Another thing, I have used .srt files for this exporting and importing before. But now it is being saved as a .st file
Why? What is the difference between .srt and .st?
Did the SpeedTree devs just decide that they want to start using .st instead of .srt or is there some significance to this meaning that it is a totally different file type?

thaank you