Page Navigation in WordPress

Hi Everyone,

>> WordPress Problem – Not Related to Active Theme <<

Across my entire WordPress Site regardless of location on the Site I have lost Page Navigation with the Previous or Next Page Options having disappeared. I am looking for an urgent fix to get Pagination and Page Numbers working.
If you look at the Posts page for example I am getting the full list of Posts on the Page. https://kewgardener.com/plants. What I would like to have is 10 Posts per Page with the Page Options (Page 1 2 3 4 5 … ) on the Top of the Posts Page and at the Bottom of the Posts Page.

Please help this is driving me nuts!

The page I need help with: [log in to see the link]