albert.lol/pages/_error.tsx

import { GetServerSideProps } from 'next'
import FadeIn from 'react-fade-in'
type ErrorPage = {
    statusCode: number,
    message: string
}

export default function({ statusCode, message }: ErrorPage) {
    return (
        <FadeIn>
            <div className='flex flex-col justify-center items-center h-[90vh]'>
                <div>
                    <h1 className='font-semibold text-2xl inline-block mr-[1.7rem] pr-[1.5rem] border-r-[1px] border-white'>{ statusCode }</h1>
                    <div className='inline-block text-left'>
                        <h2 className='text-lg font-extralight'>{ message }</h2>
                    </div>
                </div>
            </div>
        </FadeIn>
    )
}

export const getServerSideProps: GetServerSideProps = async(props) => {
    const { res, err }: any = props

    const statusCode = res ? res.statusCode : err ? err.statusCode : 404

    let entries: any = {
        404: 'Az oldal nem található',
        400: 'Érvénytelen kérelem',
        500: 'Szerveroldali hiba'
    }
    const message = entries[statusCode]

    return {
        props: {
            statusCode,
            message
        }
    }
}