canonical pagination

Hello.
The blog I manage uses rank math. The home page, as well as the categories, have pagination. From the second page on, the rel canonical is absent. I’ve already tried to follow your advice by adding the suggested codes to the functions.php file but it doesn’t work for me. I also know that the canonical about pagination only works if you use the blog page. But I need to insert the self-referential canonical to the pagination of the home and of the categories. I would like you to help me please. Thanks.