How to config github oauth2 passport.js?

Question

I use github oauth2 passport.js. After first time logged in my app auto logged in. I think this problem this prompt config. But it is not worked. Here my code:

router.get('/auth/github', 
passport.authenticate('github',{ 
    scope: [ 'user:email' ], 
    prompt: 'select_account' 
}));