Based on the text provided, you are likely looking for Graillon 2 by Auburn Sounds, which is the industry standard for a "pitcher" or pitch-correction plugin. Another common option is the classic GSnap.
He looked closer at the interface. The small text he had ignored before—the version number—flickered. pitcher vst plugin free download link
MAutoPitch by MeldaProduction: A robust alternative that offers more "utility" features than the original Pitcher. Based on the text provided, you are likely
Placement: Place Pitcher first in your mixer's effect chain. Effects like reverb or delay can confuse the pitch detection. Free Alternatives Based on the text provided