In order to a whitelist domain, you can add the domain name under DNS Filtering
You can add the domains manually or upload them in a .csv format if have multiple domains to be whitelisted. To whitelist a wildcard domain, we need to list the wildcard domain in a CSV format and import it under DNS filtering list.
NOTE: Make sure that the .CSV file contains only one column, and that every cell contains one URL (as shown in the example below). The file must contain no more than 1000 addresses. Each address must follow the form domain.com (i.e without www/HTTP/HTTPS prefixes)