How to make a clickable table of contents in pdf using mpdf?

Question

PHP

I collect pdf here and there will be quite a lot of pages. I want to make a table of contents, so that you can click on the link and go to the desired page.
The problem is that I don't understand how to do it. In the documentation it is somehow ornately described. Maybe someone knows how to insert an anchor into a page / block in pdf in pdf? Maybe there is some general rule for the design of such links for pdf?
The templates themselves are html, the library through which I collect is mpdf.