Conversely, I remember mom giving me M&Ms for getting math flash cards right as a small kid. For some reason, I always liked math...
I am not going to pretend I know how to make seemingly-boring subjects interesting, but a lot of things do need to be learned that aren't always fun.
I've always liked math [1], but I know a lot of people don't. Even still, I think having basic and intermediate math skills is important. I have no idea how to make math fun for people that actively don't like it.
[1] And I don't think I was given M&Ms for it :(
So for at least some students, there might be some potential in convincing them that "it's what the big kids / cool kids / etc can do" might help motivate them. :)
Maybe briefly show how that adavanced topic will be taught and let them realize they can not possible even start to understand advanced topic because they are missing the more elementary pieces.
Similarly why they can't got further without doing their homework. How mastering the homework exercises let's you solve more problems.
I know that is not easy, the teacher may not quite understand how topics relate, why each of them is needed in a specific order, if they have not thought about that much.