Janar

With this plugin you can add extra HTML or just plain text when posting a new page or post. That content will be displayed in sidebar widget. It is tested from WP 2.6 to 3.0.1.

ax-sidebar

With this plugin you can add extra HTML or just plain text when posting a new page or post. That content will be displayed in sidebar widget.

oceanwp

Amit Singh

Generates an unlimited number of sidebars and place them on any page you wish. Go to Theme Panel > Sidebars to create your custom sidebars. 
This plugin requires the <a href="https://oceanwp.org/" rel="nofollow ugc">OceanWP</a> theme to be installed.

Ocean Custom Sidebar

This little free plugin allowed me to easily add any Elementor Library Item to any menu in any area. Show video's, products, forms anything you like in your menu's of sidebars.

Really, REALLY useful!

Do NOT underestimate it's power!

Generates an unlimited number of sidebars and place them on any page you wish. Go to Theme Panel > Sidebars to create your custom sidebars.

ax-sidebar vs Ocean Custom Sidebar