Canonical pages

Hi,

For pagination my links are example.com/?start=24 , example.com/?start=48 ...
As canonical is set example.com/page2 , example.com/page3 but this pages does not exist.
How can I change it for existing /?start=24 or rename this not nice url ?

I did no changes, so it is basicly seted in Mosets, dont understand how it can be set for /page2 if this site does not exist.

Do I need to create external link as hidden menu for /page2 ... ?

Any help will be appreciate

Peter