So, a few things to address here.
Firstly, WP2Static is unlikely to help with the desired outcome. Yes, it will allow to export the page as HTML for local editing outside of WordPress, it won’t help address the issue of serving that one long page as multiple pages.
Whilst I may not be understanding the desired outcome exactly, it sounds to me like you want to change the site’s structure, so that each of these pages has it’s own URL, ie
https://example.com/page1name (page 1)
https://example.com/page2name (page 2)
https://example.com/page3name (page 3)
https://example.com/page4name (page 4)
What you mentioned about using
<!-- newpage--> should work fine to achieve something similar, with
This looks to cover the options: https://wpcompendium.org/create-posts/how-to-split-long-wordpress-posts-into-multiple-pages/
You may still like to use WP2Static for final delivery of your site, but it generally doesn’t affect the structure or content of your site.
If you’re trying to grab the HTML view of your page while editing, you can switch WordPress’s “block editor” to show the HTML code instead.
Hope that helps. I don’t do a lot of actual WordPress site content work these days, so if you’re still stuck on this, please reply and someone more expert may reply