Engine not revving up only reaches 2,000 RPMs then dropping down

Just to be sure, when you are doing this are you in park or when you are driving?

Once we understand this then we can figure out the best course of action.

If you are in park then this may be normal because the RPM is limited when not in gear.

However, if you are driving then we need to start with checking for codes even if you have no light on.

Here is a guide that will help with this:

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

We don't have this vehicle in the USA, so I have to use the manual from the sister vehicle. This shows the vehicle has an electronic throttle body so can you confirm that there is no cable that operates the throttle body?

Basically, push the accelerator and watch the throttle body and see if a cable is moving the plate.

I attached the process below to show more details.

Let's start with this info and go from there.

Thanks