Since WordPress 5.8 and Jetpack 10.0 launched the Block Widgets functionality, you must install and activate the Classic Widgets plugin https://wordpress.org/plugins/classic-widgets/ so you'll continue to use the standard interface and options as described below.
Step 1: How to add widgets to the sidebars
WordPress Widgets add content to your Sidebars and Footer/Body Top Widget Areas. Widgets require no coding experience or expertise. They can be added, removed, and rearranged in the WordPress Widgets panel found in WordPress Dashboard > Appearance > Widgets
Body Sidebars / Widget Areas / Widgets
- Go to Appearance > Widgets.
- Choose a Widget and drag it to the sidebar on the right, where you wish it to appear.
- Once you drop the widget to a widget area, WordPress automatically saves and updates the configuration. To arrange the Widgets within the widget area, click on the title and drag it into the place you want. To customize the Widget features, click on the icon on the right to expand the Widget's panel. To save the Widget's customisation, click "Save". To remove the Widget, click "Delete".
- Control the Widgets' visibility following the instruction below.
See the next step below
Step 2: Widget Visibility Module
This tutorial is kindly provided by the plugin developer. You can access the full plugin's documentation on this URL: https://jetpack.me/support/widget-visibility/
Control which pages your widgets appear on with Widget Visibility.
To control visibility, expand the widget and click the Visibility button next to the Save button, and then, choose a set of visibility options.
For example, if you wanted the Archives widget to only appear on category archives and error pages, choose "Show" from the first dropdown and then add two rules: "Page is 404 Error Page" and "Category is All Category Pages."
You can also hide widgets based on the current page. For example, if you don't want the Archives widget to appear on search results pages, choose "Hide" and "Page is Search results."
The Widget Visibility module enables you to configure widgets to appear only on certain pages (or be hidden on certain pages) by using the Visibility panel.
The Visibility button is next to the Save button.
Visibility is controlled by five aspects: page type, category, tag, date, and author. For example, if you wanted the Archives widget to only appear on category archives and error pages, choose “Show” from the first dropdown and then add two rules: “Page is 404 Error Page” and “Category is All Category Pages.”
You can also hide widgets based on the current page. For example, if you don’t want the Archives widget to appear on search results pages, choose “Hide” and “Page is Search Results.”
Each visibility rule is handled separately. There isn’t a way, for example, to only display a widget on posts categorised as “Summer” and tagged with “Picnic.”
If you don't see the Visibility button, please check this solution https://beaver.support.vamtam.com/support/solutions/articles/254329-how-do-i-remove-the-sidebars-and-widgets-
Another solution is to check if the Widget visibility feature is enabled here:
Step 3: How to edit the Body/Footer sidebars layout
This theme comes with Body and Footer pre-build layouts:
To edit the Footer Widget Areas width, please go to Customizer > Footer
If you don't select an Area's width it won't be visible.
If there aren't any widgets added to the Widget Areas they won't be active/visible as well. Once you add a widget to the Widget Area, it will appear.
Step 4: How to edit the Widgets' sidebars content
You can edit easily preview and modify each page's sidebars as well as the footer widgets areas. Simply open the page, next open the Customizer, select Widgets, and click on the pencil icon to edit the widget you wish: