The statement that Cloudflare uses HTTP to connect to your website can be false depending on how you configure it. For years, I have had personal websites with Cloudflare as the CDN and with Let’s Encrypt providing certificates on the web server. All I do is choose Full (Strict) in the TLS settings on Cloudflare. So the connection between the end user to Cloudflare and from Cloudflare to my web server are on HTTPS. No deactivation of Cloudflare required on my end during renewal (my web host, like many others, has the certificate generation automated and getting a TLS certificate just a toggle on my admin dashboard).