set cookies in route handler not set except get method

[Nader-CS]

hi , i have this issue

import { cookies } from "next/headers";
import { NextResponse } from "next/server";

export async function POST() {
  const res = await fetch(`${process.env.API_URL}oauth/token`, {
    headers: {
      "Content-Type": "application/json",
    },
    body: JSON.stringify({
      grant_type: "client_credentials",
      client_id: process.env.client_id,
      client_secret: process.env.client_secret,
    }),
    method: "POST",
  });
  const data = await res.json();
  const response = Response.json(data);
  (await cookies()).set("asd", "asasdkasdkld");
  return response;
}

cookies not set , but when i use Get method it work

[icyJoseph]

I can't really reproduce. How are you invoking the POST handler?