Yes, the Canon user manual for the RF24-105mm F4-7.1 IS STM explicitly lists this lens hood as a compatible accessory: Technical Specifications section, page ENU-14: Lens hood: EW-73D (sold separately)

Yes

Hello, this aperture fits : EF-S 18-135mm f/3.5-5.6 IS USM (nano) RF 24-105mm F4-7.1 IS STM https://store.canon.ch/canon-ew-73d-streulichtblende/1277C001/

Yes, this price is correct.

This hood is compatible with EF-S 18-135mm IS USM. Lens hoods are designed for specific lenses and cannot be used with others.

There are two versions of your lens. The EW-73D fits the 18-135mm IS USM and the EW-73B fits the 18-135mm IS STM.