cloudflare_worker.js

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

async function handleRequest(request) {
  const url = new URL(request.url)
  // Check if the path starts with /blog
  if (url.pathname.startsWith('/blog')) {
    const subPath = url.pathname.replace('/blog', '')
    const githubUrl = new URL(`SOURCE_URL${subPath}`)
    try {
      const response = await fetch(githubUrl)
      // Handle errors
      if (!response.ok) {
        return new Response(`Page not found: ${url.pathname}`, { status: 404 })
      }

      const contentType = response.headers.get('Content-Type') || ''

      // Handle HTML content
      if (contentType.includes('text/html')) {
        const text = await response.text()
        const rewrittenText = text.replace(SOURCE_URL/g, 'DESTINATION_URL/blog')
        const newResponse = new Response(rewrittenText, response)
        
        // Set headers
        newResponse.headers.set('Content-Type', contentType)
        newResponse.headers.set('Location', url.toString())
        newResponse.headers.set('Cache-Control', 'public, max-age=3600')
        newResponse.headers.set('X-Content-Type-Options', 'nosniff')
        newResponse.headers.set('X-Frame-Options', 'DENY')
        newResponse.headers.set('Referrer-Policy', 'strict-origin-when-cross-origin')
        newResponse.headers.set('Strict-Transport-Security', 'max-age=31536000; includeSubDomains; preload')
        
        return newResponse
      } 
      // Handle non-HTML content (like images)
      else {
        const newResponse = new Response(response.body, response)
        newResponse.headers.set('Cache-Control', 'public, max-age=3600')
        return newResponse
      }
    } catch (error) {
      console.error(`Error fetching content: ${error}`)
      return new Response('An error occurred', { status: 500 })
    }
  } else {
    // Pass through requests not starting with /blog
    return fetch(request)
  }
}

Its nice Thanks