Manually inserting page numbers

How are you creating the pagination? Are you using the nextpage links?

<!--nextpage-->

This next page tag is similar to the more tag, but doesn’t appear by default in the wysiwyg editor.

Here’s an example of a post where I used this tag – https://www.wpyogi.com/2012/12/learning-child-theming-with-twenty-twelve/

<!–nextpage–> Is the tag I am using, yes.

The issue is with placement of the page 1,2,3 etc buttons.

general info:
plugins often dump their output at the end of the post content (via a filter acting on 'the_content') while the wp_link_pages() function is usually inserted after the_content()

you will need to create a similar filter (with higher priority) for 'the_content' to insert the pages-links before the author info etc;

https://codex.www.ads-software.com/Plugin_API#Filters

for specifics, please contact your theme’s developer for support;

this forum does not support commercial themes; https://codex.www.ads-software.com/Forum_Welcome#Commercial_Products