Saddle adapter for ergometer, noseless bicycle saddle?

Hello,

I ordered a saddle adapter for my exercise bike (see link). I don't know anything about bikes, ergometers, etc. If I order a saddle without a nose, will I need a lot of accessories to attach the saddle to the saddle adapter tube?

This is what the saddle adapter looks like:

https://www.amazon.de/-/en/exercise-universal-extension-adjustable-construction/dp/B09NRCLT9W?th=1

If so, can someone tell me what kind of fasteners I need or maybe provide a link?

thanks in advance