YA Fiction about boy who has a terminal illness and a grandpa in prison. Read around 2016-2020. Spoilers.

[Elijah]

I read this book probably between 2016 and 2020, the boy has a rich friend who is introduced and (LOTS OF SPOILERS) dies in a car crash and leaves him everything. He meets a girl with cancer and the grandpa convinces him to go out with her, even though he is terminally ill. I think that he visits the grandpa in prison a lot. I remember that the grandpa gets paroled later in the book. I want to write an essay for my comp class about this book because it really affected me, but I can't remember the name :(