https://www.btstories.com/josephs-family-reunion/

Jacob heard there was grain in Egypt, so he sent his ten oldest sons to go and buy food. He didn’t send Benjamin because he was afraid of losing him.

When they arrived in Egypt, they went before the governor of the land. They didn’t know it was Joseph. He recognized them, but pretended not to know them. He wanted to test them to see if they had changed.