Using Cloudflare Workers and https://Apility.io API to block access to the pages filtered if the IP belongs to a blacklisted IP address of the service

cloudflare-workers-block-blacklisted.js

addEventListener('fetch', event => {
  event.respondWith(fetchAndCheckOrigin(event.request))
})

async function fetchAndCheckOrigin(req) {
  try {
    const body = await req.body;
    const ip = req.headers.get('cf-connecting-ip');

    const apilityio = await fetch('https://api.apility.net/badip/' + ip + '?token=APILITY_IO_API_KEY');
    const status = await apilityio.status;

    if (status == 200) {
      // The IP has been found in any blacklist
      return new Response('Sorry, you cannot access this site from this IP: ' + ip,
          { status: 403, statusText: 'Forbidden' })
    }
    if (status == 429) {
      // Quota Exceeded. Too many requests.
      return new Response('Your Apility.io quota has run out. Please change your plan to support more traffic.',
          { status: 429, statusText: 'Too many requests.' })
    } 
    return await fetch(req)
  } catch (err) {
    console.log(err);
    return new Response('Internal Error')
  }  
}