Thanks for the replies, but I don't think I explained it good enough. On my index.php page, I have a log in button, not any forms where I can put my username or password, if I'm not logged in, then the button is redirecting me to a vipps API where they ask me to type my phone number. Then it opens a program (Vipps) on my phone and asks for permission to login to my account site, this works well. But when I try my logout function on my site it sends me to my index.php file and it looks like I'm logged out, but if I then push my log in button on my site it just sends me to my account without asking for permission. I have found 2 ways to log out so I can log in with a new user, and one is delete allowed browser in my Vipps app on my phone. Or using incognito mode in chrome, login and logout, close browser and try again, then I have to the process with allowing browser with my Vipps app all over.