Ederson Peka

With this plugin, you can create as much “sidebars” (widget areas) as you need, and assign them in a per-page basis. (It’s only useful if your theme supports “sidebars”.)
WARNING: Updating from versions prior to 0.2.5 requires new set up.

Unlimited Page Sidebars

This plugin does exactly what it needs to and always works. It's great.

Does exactly what it needs to!

Assign one specific widget area (sidebar) to each page.

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.

Unlimited Page Sidebars vs Ocean Custom Sidebar