What causses the error `[GET] "/api/auth/user": 405 HTTP method is not allowed.`

const sessionHeader = useRequestHeaders(["session"]);
const getCurrentUser = async (): Promise<any> => {
    try {
        const data = await $fetch("/api/auth/user", {
            method: "GET",
            headers: sessionHeader,
        });

        return data;
    } catch (err) {
        console.log(err);
    }
};

export default defineEventHandler(async (event) => {
    const body = await readBody(event);

    // const { user, session } = await validateSessionToken(sessionToken);
    console.log(body);

    return {
        status: 404,
        body: { error: "Not Found" },
    };
});