How to Set Cookies Manually in authorize Function with NextAuth.js v5?

[tranphuocloc070699]

Hi everyone,
I'm trying to implement a custom credentials provider in NextAuth.js v5 to sign in users using a username and password. The authentication works fine, but I'm running into an issue with cookies.

Here’s my situation:
In the authorize function, my external API sets a cookie in its response (via the Set-Cookie header).
However, this cookie is not reflected in the browser because the authorize function runs server-side, and the Set-Cookie header from the API response isn’t automatically applied to the browser.

How can I manually set this cookie for the browser inside the authorize function or elsewhere in the NextAuth flow? I want to ensure that the cookie from my API is properly set in the user's browser.