Physic material bounciness too weak

i’m trying to create a trampoline effects, but when I create a 2d physics material, the force of bounce is not what I want, I want it to have more power when bounced, before it hit.

I also tried this piece of code, which works, but in order to make it correct, I should flip the Y-axis direction of the vector, anyone an idea?

collider.transform.rigidbody2D.velocity =  -collider.transform.rigidbody2D.velocity * 1.5f;


I found it:

If anyone else wants to know, I rotated the force with Pi:

    Vector3 velocity = -collider.transform.rigidbody2D.velocity;
    velocity = Quaternion.Euler(0, 180, 0 ) * velocity;
    collider.transform.rigidbody2D.velocity =  velocity * 2f;

A picture of what it does: