curl --request GET \
  --url https://api.hubapi.com/cms/v3/domains/{domainId} \
  --header 'Authorization: Bearer <token>'

{
  "id": "3210329704",
  "createdAt": "2017-07-11T13:00:52.928Z",
  "updatedAt": "2019-10-08T16:54:57.165Z",
  "domain": "99558489.hubspot.com",
  "isPrimaryLandingPage": false,
  "isPrimaryEmail": false,
  "isPrimaryBlogPost": true,
  "isPrimarySitePage": false,
  "isPrimaryKnowledge": false,
  "isResolving": true,
  "isManuallyMarkedAsResolving": false,
  "isHttpsEnabled": true,
  "isHttpsOnly": false,
  "isUsedForBlogPost": true,
  "isUsedForSitePage": false,
  "isUsedForLandingPage": false,
  "isUsedForEmail": false,
  "isUsedForKnowledge": false,
  "expectedCname": "99558489.group39.sites.hubspotqa.net",
  "redirectTo": ""
}