How do i create this corner rectangle cutout shape [closed]

Given is my website design

But i am unable to build shapes

Like in the left bar

you can see a rectangle with a cutout

so could anyone please tell me how can i create that?

I was able to create that shape but unable to make border-radius for the corners

I tried clip-path, polygon, ::before chatgpt

and other many webs nothing worked

so i thought someone might be able to help me here :D