Use this code for .htaccess to host games from another domain:
You'll need to change the domain name(s) for these codes. These examples use example.com & exampletwo.com.
Multiple sites:
<IfModule mod_headers.c>
SetEnvIf Origin "http(s)?://(www\.)?(example.com|exampletwo.com)$" AccessControlAllowOrigin=$0
Header add Access-Control-Allow-Origin %{AccessControlAllowOrigin}e env=AccessControlAllowOrigin
Header merge Vary Origin
Header set Access-Control-Allow-Methods "GET, POST, OPTIONS"
Header set Access-Control-Allow-Headers "Content-Type, Authorization"
</IfModule>
Single site:
<IfModule mod_headers.c>
Header set Access-Control-Allow-Origin "https://example.com"
Header set Vary "Origin"
Header set Access-Control-Allow-Methods "GET, POST, OPTIONS"
Header set Access-Control-Allow-Headers "Content-Type, Authorization"
</IfModule>