If the domain is very new, DNS propagation may hold up deployment of your site to all the corners of the world. To fix this, release and renew your IP, clear your cache and if that doesn’t work, wait 72 hours, it should be completed by then.
If the domain is old, it could have expired. Log in to my.Freenom.com to renew it. How to renew Freenom domain: https://my.freenom.com/knowledgebase.php?action=displayarticle&id=2