Add libraries to script task

Hi,

I want to use function that are not included in System library/package.

I need to add the following in order to use the functions.

using System.Linq;

I tried adding this to the script but got an error message: " Feature 'using declarations' is not available in C# 7.3. Please use language version 8.0 or greater."

Is there a way to add the 'System.Linq' somewhere?

Thanks,

Chani