How to generate refresh token?

[rba1aji]

I have client id, client secret, access token, access token secret, bearer token, consumer key, consumer secret.

But I need to get refresh token to make this

        TwitterApi twitter = new TwitterApi(
                new TwitterCredentialsOAuth2(
                        clientId, clientSecret, accessToken,refreshToken
                )
        );

How can I generate this refresh token?