@paul2009 Thank you for sharing the steps!
For anyone stuck on step 6, you'll enter an @ symbol into the host field, no other text. (see attached screen shot.) Here is the article where I found the information: https://developers.facebook.com/docs/sharing/domain-verification/verifying-your-domain/.
I also found this video helpful: https://youtu.be/x28TGYX9NW4