You don't want to allow it, what you're looking at is a fake Java update that is an adware/malware bundler - it tries to trick you into thinking you're updating your java, but you're not. Malwarebytes is protecting you from your attempts to accept a virus!
Doesn't sound like a "verified safe" website, to be honest. It might be a good site with a bad ad (hard to tell) but it sounds like it is trying to make you download that to continue - in which case avoid the site like the plague, and scan your system for malware from your last visit.