Do I need a visa or no?

Hello everyone
I couldn't find an answer to my question, so I am trying here.
I need to do an internship in Brussels, Belgium in the summer, I got accepted and everything. I have a non-Eu citizenship but I study in Italy with a valid residence permit. I will do the internship under Erasmus+ program and it's to be exact 90 days.
My question is do I need a work permit or single permit or I don't need anything at all? unfortunately the embassy is not helpful here. so anyone who have the same or almost the same experience. I would like to have some answers.
I know here is not the best place to ask, but believe me I tried other ways.

Thank you

Welcome to the forum.

Have you tried to contact teaching institutions for advice.