SEO + AJAX how do they work together?

Question

Search Engine Optimization

Good afternoon everyone. Found 2 ways to index pages with ajax.
1 Using HIJAX (deprecated)
2 Using the "!"
While reading the article, I did not quite understand how it works and what link should be in href="link"
I would be very happy if someone could explain normally and show the JS + HTML code as an example

Answer 1

Do you have SPA?
Here are recommendations for working with SPA and rendering .