How to logout a user and clear passport session as admin?

So I have an authentication based on passport that uses local strategy and Redis for session storage. I know that when a user wants to log out himself, a logout API can be provided like this:

router.post('/logout', (req, res) => {
    req.logout(null, () => {
        res.send("logged out");
    });
});

But is there a way to log the user out as the website admin? Maybe by deleting redis directly? But how can I get the corresponding user key?