How to "conceal" an external website inside of a squarespace member area

In our member area we want to have a videos site.

Curiously, we already have a videos site developed. We can put it in the members area via an <embed> tag for a very crude proof of concept.

We need, however, for that web site to not be visible on the open internet. Site is linux/apache2.

Looking for ideas how to implement this.

You can create a video are under the Not Linked pages area and create a link to it.

I also found this on Squarespace that might help https://support.squarespace.com/hc/en-us/articles/360050366952-Getting-started-with-Member-Areas