I am looking for the name of this:
It is a vehicle with a long band where you can adjust the angle of the band.
This category of equipment is known as "Ground Support Equipment" (see Wikipedia article).
This includes a variety of utility vehicles, including refuelers, dollies, chocks, buses and more.
However, the one you're after is the Belt loader:
Belt loaders are vehicles with conveyor belts for unloading and loading of baggage and cargo on aircraft. A belt loader is positioned at the door sill of an aircraft hold (baggage compartment) for the operation. Belt loaders are used for narrow body aircraft and bulk hold of wide body aircraft. Baggage stored without containers is known as bulk loading.
I just found it in Ground support equipment:
It is called "Belt loader".