`oauth2/token` endpoint returns 502 Bad Gateway error

import { Hono, type Context } from "hono";
import { GrantType } from "@kinde-oss/kinde-typescript-sdk";

const api = new Hono();

api.get("/my-route-path", async (c: Context) => {
  const url = new URL(c.req.url);
  const authCode = url.searchParams.get("code");
  const response = await fetch(`${KINDE_SUBDOMAIN}/oauth2/token`, {
    method: "POST",
    body: JSON.stringify({ 
      client_id: KINDE_CLIENT_ID,
      client_secret: KINDE_CLIENT_SECRET,
      grant_type: GrantType.AUTHORIZATION_CODE,
      redirect_uri: KINDE_REDIRECT_URL,
      code: authCode,
    }),
    headers: { "Content-Type": "application/json" },
  });
});

{
  ok: false,
  url: "https://my-kinde-subdomain/oauth2/token",
  status: 502,
  statusText: "Bad Gateway",
  headers: Headers {
    "date": "Tue, 14 Jan 2025 02:03:49 GMT",
    "content-type": "text/html",
    "content-length": "122",
    "connection": "keep-alive",
    "server": "awselb/2.0",
  },
  redirected: false,
  bodyUsed: false,
  Blob (122 bytes)
}