404 Error

import { createAuthClient } from "better-auth/react";
import { usernameClient } from "better-auth/client/plugins";
import { polarClient } from "@polar-sh/better-auth";

export const authClient = createAuthClient({
  baseURL: process.env.NEXT_PUBLIC_APP_URL || "http://localhost:3000",
  plugins: [polarClient(), usernameClient()],
});

...
export const auth = betterAuth({
  secret: process.env.BETTER_AUTH_SECRET!,
  baseURL: process.env.NEXT_PUBLIC_APP_URL!,
  database: drizzleAdapter(db, {
    provider: "sqlite", 
  }),
});

import { auth } from "@/lib/auth"; // path to your auth file
import { toNextJsHandler } from "better-auth/next-js";

export const { POST, GET } = toNextJsHandler(auth);

"better-auth": "^1.2.12",
"react": "^19.0.0",
"next": "15.3.5",