Font weight not Applicable

I use Cascadia Code font and use font weight 350 but when i change it in json file font weight doesn't change. I checked 200, 300, 500 but it shows only normal font weight which is 400.

<img width="550" height="159" alt="Image" src="https://github.com/user-attachments/assets/de42f69f-5825-4daf-b4ef-4c8b363f86b3" />