Module signing

Hi, I signed my module with Symantec code singing certificate, but when importing it I get that it’s from untrusted publisher. Why is that?

Have a look at Hey, Scripting Guy! How Can I Sign Windows PowerShell Scripts with an Enterprise Windows PKI? (Part 2 of 2) - Scripting Blog

I already looked there. Whats the point of buying code signing certificate if you still have manually to import it to Trusted Publishers?