Why are GET/POST requests not working on WP?

Question

HTTP headers

Hello!
I send a search form (GET / POST tried both options) to another page, where, depending on the data received, it displays records (The page has a template installed)
However, with this transition, it shows the main page template
Help me figure it out

Answer 1

You can for example like this:

function add_query_vars_filter( $vars ){
       $vars[] = "название_переменной";
       $vars[] = "название_второй_переменной";
       return $vars;
  }
  add_filter( 'query_vars', 'add_query_vars_filter' );

And receive like this:

$var = (get_query_var('название_переменной')) ? get_query_var('название_переменной') : false;