Search for "Keylight (1.2)" and drag it onto your green screen layer.

Uses advanced algorithms to distinguish foreground subjects from background screens.

In the Effect Controls panel, use the Eyedropper tool to sample the background color from your footage.

To achieve the best results without needing third-party downloads, Adobe experts at the Adobe Help Center recommend using Keylight in tandem with two other built-in tools:

Allows users to switch between views like "Screen Matte" or "Status" to identify and fix holes in the key.