How can I make sure the code gets run on the client-side??!

import { useEffect, useState } from "preact/hooks";

export default function Callback() {
    useEffect(() => {
        const hashParam = window.location.hash.substring(1);
        console.log(`Param: ${hashParam}`);
       
    }, []);

    return (
        <div>
            ....
        </div>
    );
}