docs: clarify getToken + secret in example

ref #4954

Author: balazsorban44

apps/dev/pages/api/examples/jwt.js

@@ -2,6 +2,6 @@
 import { getToken } from "next-auth/jwt"
 
 export default async (req, res) => {
-  const token = await getToken({ req, secret: process.env.SECRET })
+  const token = await getToken({ req })
   res.send(JSON.stringify(token, null, 2))
 }

apps/example-nextjs/pages/api/examples/jwt.ts

@@ -3,12 +3,12 @@ import { getToken } from "next-auth/jwt"
 
 import type { NextApiRequest, NextApiResponse } from "next"
 
-const secret = process.env.NEXTAUTH_SECRET
-
 export default async function handler(
   req: NextApiRequest,
   res: NextApiResponse
 ) {
-  const token = await getToken({ req, secret })
+  // If you don't have the NEXTAUTH_SECRET environment variable set,
+  // you will have to pass your secret as `secret` to `getToken`
+  const token = await getToken({ req })
   res.send(JSON.stringify(token, null, 2))
 }