There are specific mod menus created by developers under the alias "Reaper" for various games.
: You can right-click any blank area in the Track Control Panel (TCP) to customize menus, add virtual instrument shortcuts, or insert specific track templates. REAPER MOD MENU Download
: These are typically installed via a repository zip file (e.g., repository.redditreaper-1.*.zip ) and managed through the Reaper Wizard add-on. There are specific mod menus created by developers
Which specific version of were you looking to download and install? GTA-Style Menus in REAPER? (Radial Menu) add virtual instrument shortcuts