Next Auth doesn't work with custom basePath - next.js

Question

My NextAuth are returning 404 when searching for api/auth/session at credential provider custom login, seems like Next Auth are pointing to the wrong url.
My next.config.js have a basePath that points to a subfolder basePath: '/twenty-test' and my NEXTAUTH_URL is already set to my subdomain,
but when I go to my credential provider login custom page (that was working at localhost because it was not at a subdomain), i see an 404 error at console like https://explample.com/api/auth/session 404.
This is my custom provider config:
providers: [
CredentialProvider({
name: 'Credentials',
type: 'credentials',
async authorize(credentials) {
//
if(credentials.email == "john#gmail.com" && credentials.password == "test"){
return {
id: 2,
name: 'John Doe',
email: 'john#gmail.com',
permition: {
group: 2,
level: 0
}
}
}
return null;
}
})
],
This is my next.config.js
const nextConfig = {
reactStrictMode: true,
basePath: '/twenty-test',
images: {
domains: ['example.com'],
},
}
module.exports = nextConfig
This is my NEXTAUTH_URL env variable
NEXTAUTH_URL="https://example.com/twenty-test/api/auth"
This is my getCsrfToken config
export async function getServerSideProps(context) {
return {
props: {
csrfToken: await getCsrfToken(context)
}
}
}
My project are not on vercel. I'm using a custom server config to deploy with cPanel

Answer 1

The problem was on building the app in localhost and deploying on server.
The app was building expecting NEXTAUTH_URL as localhost, and simply changing the .env variable on server didnt worked.
The solution was building the app on server.
Another workaround was replacing the localhost NEXTAUTH_URL ocurrences after building with the value of NEXTAUTH_URL on server.