This is the screenshot

this is the server error log generated

[Sat Oct 23 19:39:50.880944 2021] [:error] [pid 14841:tid 47226270963456] [client 61.245.170.73:48465] [client 61.245.170.73] ModSecurity: Warning. Match of "rx \\/wc-api\\/KCO_WC_Validation\\/" against "REQUEST_URI" required. [file "/etc/apache2/conf.d/modsec_vendor_configs/imunify360-full-apache/002_i360_1_infectors.conf"] [line "51"] [id "77140164"] [msg "IM360 WAF: Infectors: PHP Injection Low value||T:APACHE||MVN:REQUEST_URI||MV:/wp-admin/admin-ajax.php||SC:/home2/mrcstude/ictknowledgehub.com/wp-admin/admin-ajax.php"] [severity "DEBUG"] [tag "service_o"] [tag "service_i360"] [hostname "www.ictknowledgehub.com"] [uri "/wp-admin/admin-ajax.php"] [unique_id "YXRlBmtzrVqCoVAH4CfJFgAATws"], referer: https://www.ictknowledgehub.com/wp-admin/plugin-editor.php?file=MLM%2Fincludes%2Fadmin%2Fjs%2Fblm.admin.ajax.js&plugin=MLM%2Fbinary-level-marketting.php

this is the javascript file

jQuery( document ).ready( function( $ ) {

/**
* The file is enqueued from inc/admin/class-admin.php.
*/
$( ‘#nds_add_user_meta_ajax_form’ ).submit( function( event ) {

    event.preventDefault(); // Prevent the default form submit.            
    
    // serialize the form data
    var ajax_form_data = $("#nds_add_user_meta_ajax_form").serialize();
    
    
    //add our own ajax check as X-Requested-With is not always reliable
    ajax_form_data = ajax_form_data+'&ajaxrequest=true&submit=Submit+Form';
    console.log(ajax_form_data);
    $.ajax({
        url:    params.ajaxurl, // domain/wp-admin/admin-ajax.php
        type:   'post',                
        data:   ajax_form_data
    })
    
    .done( function( response ) { // response from the PHP action
        $(" #nds_form_feedback ").html( "<h2>The request was successful </h2><br>" + response );
    })
    
    // something went wrong  
    .fail( function() {
        $(" #nds_form_feedback ").html( "<h2>Something went wrong.</h2><br>" );                  
    })

    // after all this time?
    .always( function() {
        event.target.reset();
    });

}); 

});

this is the response function

function save_member_ajax () {
    
        //ajax processing
        if( isset( $_POST['ajaxrequest'] ) && $_POST['ajaxrequest'] === 'true' ) {
            
        // server response
        echo '<pre>';                   
          print_r( $_POST );
        echo '</pre>';
            
        $mb = new Member();
        $mb->setMemid($_POST['memid']);
        $mb->setParent_ID($_POST["parentid"]);
        $mb->setUsername($_POST["username"]);
        $mb->setPassword($_POST["password"]);
        $mb->setFirstname($_POST["firstname"]);
        $mb->setLastname($_POST["lastname"]);
        $mb->setOptgender($_POST["gender"]);
        $mb->setBirthdate($_POST["birthdate"]);
        $mb->setAddress($_POST["address"]);
        $mb->setCity($_POST["city"]);
        $mb->setState($_POST["state"]);
        $mb->setCountry($_POST["country"]);
        $mb->setPincode($_POST["pincode"]);
        $mb->setMobile($_POST["mobile"]);
        $mb->setEmail($_POST["email"]);
        $mb->setImage($_POST["image"]);
        $mb->setACC_FLAG($_POST["ACC_FLAG"]);

        $mb->Insert();
        
        wp_die();
      }

this is the action hook

$this->loader->add_action( 'wp_ajax_nds_form_response', $plugin_admin, 'save_member_ajax');

hope your valuable suggestions !!!