But your domain doesn't have a valid certificate, so Cloudflare blocks with a http status 521.
Error 521 Ray ID: 4b7fe7f61bf42d95 • 2019-03-15 16:36:24 UTC Web server is down You Browser Working Berlin Cloudflare Working www.hieucredit.com Host Error What happened? The web server is not returning a connection. As a result, the web page is not displaying. What can I do? If you are a visitor of this website: Please try again in a few minutes. If you are the owner of this website: Contact your hosting provider letting them know your web server is not responding. Additional troubleshooting information . Cloudflare Ray ID: 4b7fe7f61bf42d95 • Your IP : 2a01:238:301b::1229 • Performance & security by Cloudflare
So
if I know it correct, there is an integrated Cloudflare solution you can use (or)
remove Cloudflare, then create a certificate, then activate Cloudflare again.
If you tell Cloudflare that your site requires a valid certificate, your site must already have one. Otherwise, you've done this in the wrong order. Enforcing the certificate validity when the certificate doesn't exist prevents you from issuing the certificate.
The integrated solution that @JuergenAuer mentioned is CloudFlare Origin CA; this is at least as secure as a Let's Encrypt certificate in this setting and more convenient, as long as you don't ever need to disable Cloudflare (if you do, you'll need to replace the certificate).
How do I make my website work again, I use namsilo domain name and wordpress vps at google cloud, now I just want my website to work, not the sll certificate. can you help me thank you