Op-in to the vendors page

Hello guys,

I have a YT video which I send all the visitors to it directly to the vendor page. The vendor page doesn't have any op-in or squeeze page, I don't like to create a landing page right now, so I am wondering can I add an op-in to the vendor site to collect emails?? Is there any method?

Thank you.

How can I put a lamp in your house? I can't, unless I ask you to do it for me.
It's the same ffor what you asked, you can't put an Opt-in on someone else's website.