Hi Ahmed,
Thanks for sharing the information about the SCSS file location.
We can find the details about how to use SCSS files for Syncfusion blazor components below.
https://blazor.syncfusion.com/documentation/appearance/theme-studio/
https://blazor.syncfusion.com/documentation/common/how-to/customize-font-size-and-color/
Regards,
Muthukumar K