Sure! (Thank you for the fast answer btw 
)
POST:
https://api.twitch.tv/kraken/oauth2/token?client_id=<clientid>&client_secret=<clientsecret>&code=<code>&grant_type=authorization_code&redirect_uri=<redirecturi>
Response:
{
"access_token": "<accesstoken>",
"refresh_token": "<refreshtoken>",
"scope": [
"openid"
]
}