You're importing a component that needs next/headers. That only works in a Server Component but one of its parents is marked with "use client", so it's a Client Component.

  useEffect(() => {
        const fetchAndSet = async () => {
            const response = await fetchServerWrapper("/posts", "GET", {});
            const json = await response.json();
            console.log(json);
        }

        fetchAndSet();
    }, [filters]);

export async function fetchServerWrapper(endpoint: string, method: string, body: Record<string, unknown>) {
    const token = await getToken();
    return await fetchWrapper(token ?? "", endpoint, method, body);
}

export async function getToken() {
    const token = cookies().get('token')?.value
    return token;
}

PlainTable.tsx:27 Uncaught (in promise) Error: Only plain objects, and a few built-ins, can be passed to Client Components from Server Components. Classes or null prototypes are not supported.

export default async function fetchWrapper(token: string, endpoint: string, method: string, body: Record<string, unknown>) {
    const response = await fetch("http://127.0.01:8080/" + endpoint, {
        headers: {
            'Authorization': `Bearer ${token}`,
            'Content-Type': 'application/json',
            credentials: 'include',
        },
        body: Object.keys(body).length > 0 ? JSON.stringify(body) : undefined,
        method
    });
    return response;
}