AMP Access Control Allow Source Origin header Issue

Question

How can I resolve the error below;

Failed to load resource: the server responded with a status of 500 (Internal Server Error) cdn.ampproject.org/v0.

Answer 1

This may save a head ache or two. I went round in circles quite a while;

Be aware in the recognized answer above that if https://example.com happens to be a domain name with hyphens in it, the string replacement will not give the desired result.

For example https://www.my-domain.com needs to be turned into https://www-my--domain-com and it won't be.

header("Access-Control-Allow-Origin: ". str_replace('.', '-','https://www.my-domain.com') .".cdn.ampproject.org");

Needs to be

header("Access-Control-Allow-Origin: https://www-my--domain.com.cdn.ampproject.org");

So

$h = 'https://www.my-domain.com';
$h = str_replace('-', '--',$h);
$h = str_replace('.', '-',$h).'.cdn.ampproject.org';

then

header("Access-Control-Allow-Origin: " . $h);