RStudio key bindings / shortcuts. See the entry for "commentUncomment" – multiple bindings possible. To find out where to save, see section "Saving and Loading" in https://support.rstudio.com/hc/en-us/articles/206382178-Customizing-Keyboard-Shortcuts-in-the-RStudio-IDE#:~:text=Saving,Kevin

rstudio_bindings.json

{
    "goToFileFunction": "Ctrl+P",
    "insertPipeOperator": "Ctrl+Shift+M",
    "restartR": "Ctrl+R",
    "activateTerminal": "Ctrl+3",
    "browseAddins": "",
    "closeProject": "",
    "closeTerminal": "",
    "sendTerminalToEditor": "",
    "newTerminal": "Ctrl+T",
    "nextTerminal": "Ctrl+6",
    "previousTerminal": "Ctrl+5",
    "clearPlots": "",
    "activateVcs": "Ctrl+7",
    "switchToTab": "",
    "lastTab": "Ctrl+9",
    "nextTab": "Ctrl+M",
    "layoutZoomVcs": "Ctrl+Shift+4",
    "layoutZoomCurrentPane": "Ctrl+0",
    "layoutZoomHistory": "",
    "layoutZoomPlots": "Ctrl+Shift+5",
    "loadWorkspace": "",
    "reloadPlumberAPI": "",
    "toggleToolbar": "Ctrl+J",
    "toggleTabKeyMovesFocus": "",
    "addCursorBelow": "Ctrl+Alt+Down",
    "addCursorAbove": "Ctrl+Alt+Up",
    "yankAfterCursor": "",
    "yankBeforeCursor": "",
    "executeCodeWithoutMovingCursor": "Alt+Enter",
    "previousTab": "Ctrl+N",
    "firstTab": "Ctrl+Shift+1",
    "openProjectInNewWindow": "Shift+Cmd+O",
    "closeAllTerminals": "Alt+Shift+S",
    "activatePackages": "",
    "layoutZoomSource": "",
    "activateConsolePane": "Ctrl+2",
    "activateConsole": "",
    "activateHelp": "",
    "activateHistory": "",
    "buildAll": "Ctrl+Shift+I",
    "activateFiles": "Ctrl+E",
    "commentUncomment": ["Ctrl+Shift+C", "Ctrl+/"]
}