The J line is Samsung's budget line, and typically doesn't get updates for as long as their flagships. What's the exact model number of the phone? Look it up here and see what the latest known firmware is: https://www.sammobile.com/firmwares/
Thing is that the revenue/profit margins for Samsung’s budget phones are already so thin that it doesn’t justify having a dedicated software team just for cheaper models...unlike with flagship/premium devices like the Galaxy S8 or A9