Automatic subdomain creation and redirection

I would like to consult something in general. You can think of it like a portfolio site. Users will register on the site and they will be able to organize their portfolios as the subdomain of our project, for example, as username.domainaname.com. How can we serve the person's site as a subdomain. So how can we set these dns settings automatically? Thanks for your answers in advance. Can you recommend a source on this? I can give appect.com as an example site.