How to use GetInitialProps and GetServerSideProps in Next.js

export async function getPostsByName(name) {
  const result = await client.fetch(
    `*[_type == "post" && involved[]->slug.current match $name] | order(date desc) {
        title,
        'impacts': impacts[]->,
        featured,
        date,
        excerpt,
        'slug': slug.current,
        'coverImage': image,
      }`,
    { name }
  );

  return result;
}

export async function getAllPosts() {
  const result = await client.fetch(
    `*[_type == "post"] | order(date desc, _updatedAt desc) {
      title,
      'impacts': impacts[]->,
      featured,
      date,
      excerpt,
      'slug': slug.current,
      'coverImage': image,
    }`
  );

  return result;
}

export async function getStaffBySlug(slug) {
  const result = await client.fetch(
    `*[_type == "staff" && slug.current == $slug] {
      firstName,
      lastName,
      'department': department->name,
      position,
      image,
    }`,
    { slug }
  );

  return result;
}