Issue with "Not Secure message" in stead of lock icon next to domain name

My domain was purchased on Homestead but when I follow the procedures to Activate my SSL to secure my site, I get the following message when I enter my domain of academiadetrafico.com....   

DOMAIN CAN'T BE VERIFIED AS IT DOESN'T EXIST ON BUILDER

Please advise if anyone has had the same problem.  Thank you.