Polonia / Need help about sending a package from Poland to Portugal [4]

Hello :) I'm new to this forum and i was hoping someone would help me out with a problem i have ..
So, I need to send a package about 10kg from Wrocław to Portugal and i have absolutely no clue how to do it.. Do you guys think I should go to the Poczta Polska or some other company?

Thank yoooou :)