Codechef asks permissions on each login

Whenever my app logins a user using Codechef oAuth, code chef asks for permission every time even if the person has already given the permissions before.
Is this the default behaviour or there is some error in my implementation ?

@vaibhavthakkar, store access token once user authorises your app. The life time of an access token is one hour. You can use refresh tokens to get new access tokens after that.

But what if the user logs out, then when it logins again will the user be giving permissions again ?

Once you have user’s access token and refresh token(not expired), it does not matter if user is logged in or not.

Sorry, I think I didn’t explain my question well. What I was to ask is let’s say I have a web app which allows user to enter using Codechef oAuth, then the user gives the necessary permissions and is able to successfully enter the app, so now I have user’s refresh token.

Now what if user logs out of my web app so I would have to delete all his cookies, now when next time user enters he will again enter through Codechef oAuth but why is Codechef again asking the permissions ?
Because now I cannot use his refresh token without him passing through the Codechef oAuth process.
Any suggestions ?