Select any file in Finder and press the Space bar .
If you find that Quick Look cannot preview certain file types (like Markdown, JSON, or CSV), you can download specialized plugins to add support. GitHubhttps://github.com List of useful Quick Look plugins for developers - GitHub quicklook mac download
Use Command + Y or right-click a file and select Quick Look . Select any file in Finder and press the Space bar
Press the Space bar again or click the "X" in the top-left corner. Enhancing Quick Look with Plugin Downloads quicklook mac download
Since Quick Look is part of macOS, there is no standalone installer for the base feature. You already have it.