I was right about the import..
When i was trying to do:
User.UserPK userpk = new User.UserPK();
It was failing because i had an import like this one:
org.company.User.UserPK;
What I did to solve it it’s let the import like this:
org.company.User;
It allowed me to instantiate the class as an inner one.
Thanks for those who helped me.
solved How to instantiate an Embeddable class?