Where is the drupal 7 default 404 template located?

Question

Drupal

Where is the default drupal 7 template located? or the formation of its
settings, I found where /admin/config/system/site-information
I do not need to create my own template, etc.
I just need to add a link to the main one and that's it in this template

Answer 1

Must be in page--error.tpl.php, i.e. page--404.tpl.php.
But the recommended option is to just indicate the number of the node created for this at the address you mentioned.
If it does not fit, then you can install this module here: https://www.drupal.org/project/customerror