piano composing

I’m a student an I’m going to perform in a concert for school charity in probably October.
My upperclassman had already compose the majority of the piece I’m going to play. The problem is… he didn’t compose the piano part that I’m supposed to be playing, and when I asked, he told me to do an impovisation.
We haven’t had any rehersals yet. I tried to improvise at home, but I fear that it would sound ridiculous and stupid.
This piece is like just 1 minute long, and just the piano part, so i hoped the cost wouldn’t be so high.

this is a link to the piece’s sheet and mp3 : https://drive.google.com/drive/mobile/folders/1-1wOX4uL-4VdeXJSDpOmqVnJ2gH4hqdG/1-AFkA6YOcM5ULSP3GAGR2MMothMyclmz/13_ySoKVrtp5dZia1PNh_TshJMSzNYk5x?sort=13&direction=a

my improvisation would probably based on this;

could you make the piece a little more texture and i don’t know, harmonic layers?

thank you.

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