Did you put the blower under the outside pipe of the silo and attached it to a tractor as you can see on the picture posted to the blower?
I highly recommend you use the Meyer forage boxes for unloading from Skywalker Farms: https://skywalker-farms.itch.io/fs22-meyer-rt200-series
The Gehl boxes don't work. I gave it a shot on another map some time ago.