In AWS when configuring a CloudFront you are able to set a x-origin-verify header and with a long static string (sort of token) as a value. This header is checked by the origin server (in this case a load balancer) to make sure the string (token) matches. This is to make sure the request comes from the CloudFront distribution
We would like to start using Cloudflare for the DNS. Is there a way to set an equivalent header with a string (token) that a load balance can check to ensure the request comes from Cloudflare?