loggedIn.value always false

I'm actually new to Nuxt. I tried the tutorial for authentication, and it works well on my computer with docker. When I try to deploy it on my vps, I have an issue with it. loggedIn.value is always false. I check my authentication api, and it doesn't throw an error. I check the server side of nuxt and there is no error too. I can provide code if needed. I'm really confused now.