Cloudflare Worker holding page

cf-holding-page.js

addEventListener("fetch", event => {
    event.respondWith(fetchAndReplace(event.request))
})

async function fetchAndReplace(request) {

    let modifiedHeaders = new Headers()

    modifiedHeaders.set('Content-Type', 'text/html')
    modifiedHeaders.append('Pragma', 'no-cache')

    const holdingPage = await fetch(holdingPageUrl)
    const content = await holdingPage.text();
    
    // Return modified response.
    return new Response(content, {
        headers: modifiedHeaders
    })
}

const holdingPageUrl = "https://example.com"