Personalization: Create a page when you create a new site in a multi-site network?

I found this code to automatically create a page when a new site is created on the network. But I can not figure out how to set which page template will be used when the page is created.
I have a custom page template that I want to use on the page that is created automatically.

I found this post that explains how to automatically create a page when you create a new site. But what about the template of the page:
https://wordpress.stackexchange.com/a/28620/143279