Is there a script or plugin available for automatically creating websites like Wix?

[Frappuccino]

Hello, I registered the domain name fansub.site so that fansub groups can share their content under the free name.fansub.site domain when setting up their website. However, I need to manually set up the sites. They can automatically create forums for subdomains on a certain forum site. I want to do the same with WordPress. It doesn't have to be Wordpress, but is it possible to do something similar? (I don't have a budget, the service will be used for free so I don't see the need for it)