Use the "domain" field in myDSP when creating a high intent campaign
You need to match the full domain and extention (adidas.com for exemple), the brand only will not match anything ("adidas" alone does no return you any traffic when entered in brand/domain field).
Do not enter the protocol (http://, https://).
The subdomain www does not need to be entered. ("adidas.com" and "www.adidas.com" do match to adidas.com, the www. is always removed).
Subdomains have to fully match as well, no exceptions.
You may enter with or without caps as they do not matter