Some of the objects in a Julia Package are not defined

I am using Julia 1.8.1 in windows 10.

I add the SumOfSquare Package, but some of the objects are not defined. For example, if I run:

using SumOfSquares
Symmetry

I get the error: UndefVarError: Symmetry not defined

I have updated the package, removed and then added it again, but none of them works.

However, I tested this in Linux, and it's totally fine in Linux.

What is the reason?

What should I do?