Is a customizable website within the license or not?

I’m looking at getting several static backgrounds and video backgrounds to use for a website. If I allow users to create the own area within my site but choose from a list of premade themes, is this allowed under either license?

To further explain, here’s how the experience is:

  1. Bob signs up on my website. example.com.
  2. Bob creates a space: scifi-fanclub.example.com and chooses the built-in neon theme with a video background. (purchased from here)
  3. Sandy signs up and creates several spaces, one of them a cyberpunk-based one and also uses the neon theme with the video background.

Neither can download the theme as the styling is very specific to my website. i.e. it’s not made for WordPress, etc. They only have access to the theme while they have an account on my site. It’s similar to Wikia.com or World Anvil.

The license says this:
“You can’t use the Item in any application allowing an end-user to customize a digital or physical product to their specific needs, such as an “on-demand”, “made to order” or “build it yourself” application”
I interpret that be being a WordPress theme that others can download and install on their own sites. The theme never leaves my site.

If the answer is no, I can’t use the backgrounds/videos like this, is there a license, even if custom, that would allow for this kind of usage? Even if I can’t afford it now, I’d like to plan ahead.

No, that would require stand alone licenses per environment created by each user, as each one would be classified as a unique project.

There are no suitable licenses for that here .