Second side-bar not widget capable

how far have you got?
have you added the ‘dynamic code’ to sidebar.php?
and the corresponding code to functions.php?

codex docu:
https://codex.www.ads-software.com/Function_Reference/register_sidebar
https://codex.www.ads-software.com/Function_Reference/dynamic_sidebar
a possible tutorial:
https://www.quickonlinetips.com/archives/2007/11/how-to-create-multiple-dynamic-sidebars-for-wordpress-widgets/

you could copy sidebar.php into a https://wordpress.pastebin.com/ and post the link to it here.
also the same with functions.php.

sidebar.php
functions.php

The message wordpress gives me is:

No Sidebars Defined

The theme you are currently using isn’t widget-aware, meaning that it has no sidebars that you are able to change. For information on making your theme widget-aware, please follow these instructions.

i think you mixed ‘register_sidebar’ and ‘register_sidebars’ (plural):

read this again https://codex.www.ads-software.com/Function_Reference/register_sidebars , and try to follow the code example.

or, you could try in functions.php:

<?php
if ( function_exists('register_sidebars') ) {
   $args=(array(
     'name'          => sprintf(__('Sidebar %d'), $i ),
     'id'            => 'sidebar-$i',
     'before_widget' => '<li id="%1$s" class="widget %2$s">',
     'after_widget' => '</li>',
     'before_title' => '<h2 class="widgettitle">',
     'after_title' => '</h2>',
    ));
register_sidebars(2,$args); } 

?>

Thanks it works now! ??