I’m not aware of any scholarships that are solely tied to either SAT or ACT (maybe some local ones?).
Students earn National Merit Finalists by taking the PSAT (generally junior year), which must be confirmed by a qualifying score from either an SAT or ACT. There are also alternative NMF qualification pathways if one misses the PSAT. Actual scholarship $ for NMFs are becoming less common and worth less $.
https://www.nationalmerit.org/s/1758/interior.aspx?sid=1758&gid=2&pgid=424