I have never seen contributors get anything for open source contributions.
In larger, more established projects, they explicitly make you sign an agreement that your contributions are theirs for free (in the form of a github bot that tells you this when you open a PR). Sometimes you get as much as being mentioned in a readme or changelog, but that's pretty much it.
I'm sure there may be some examples of the opposite, I just.. Wouldn't hold my breath for it in general.