Call external API in wordpress based on user input

I want to create a simple wordpress website in which I want to display a search box on a page. On searching a string in text/search box, an external API call should be made based on that string and the data returned by the API should be shown to user. I have successfully referred code from below URL so far - https://rapidapi.com/blog/integrate-external-api-wordpress/.

But I am not able to make a call to API based on string passed in text box. I have done below code so for in the child theme file page:-

div id=primary ?php generate_do_element_classes( 'content' ); ?
    main id=main ?php generate_do_element_classes( 'main' ); ?
        form action= method=post
        Enter query:
        input type=text name=t1
        br
        br
        input type=submit name=s
        ?php
        /**
         * generate_before_main_content hook.
         *
         * @since 0.1
         */
        do_action( 'generate_before_main_content' );

        if(isset($_POST['s'])){
        echo good;    
        $curl = curl_init();

        curl_setopt_array($curl, [
            CURLOPT_URL = ******API URL*****/.$_POST['t1'],
            CURLOPT_RETURNTRANSFER = true,
            CURLOPT_FOLLOWLOCATION = true,
            CURLOPT_ENCODING = ,
            CURLOPT_MAXREDIRS = 10,
            CURLOPT_TIMEOUT = 30,
            CURLOPT_HTTP_VERSION = CURL_HTTP_VERSION_1_1,
            CURLOPT_CUSTOMREQUEST = GET,
            CURLOPT_HTTPHEADER = [
                x-rapidapi-host: XYZ,
                x-rapidapi-key: ABc
            ],
        ]);

        $response = curl_exec($curl);
        $err = curl_error($curl);

        curl_close($curl);

        if ($err) {
            echo cURL Error #: . $err;
        } else {
            echo $response;
        }
    }
                

        /**
         * generate_after_main_content hook.
         *
         * @since 0.1
         */
        do_action( 'generate_after_main_content' );
        ?
        /form
    /main
/div

?php
/**
 * generate_after_primary_content_area hook.
 *
 * @since 2.0
 */
do_action( 'generate_after_primary_content_area' );

generate_construct_sidebars();

get_footer();

When I click on Submit button, it gives 'Page not Found'.