There are several ways to embed a widget on WordPress:
Add widget to single page
Log in to your WordPress website's admin panel.
Click “Pages” menu option.
In the page list, find the page you want to add the widget to, and click on its name.
In the top left corner, press the “Plus” button.
In the blocks menu, type "html" in the search field.
Click on the "Custom HTML" button that appears.
At the bottom of your page, you will see an empty HTML block.
Paste the Widbox HTML code (ctrl + V) into it.
Position the created HTML block by using the arrows in the desired place.
Click the “Update” button in the top right to publish the Widbox widget on that page.
To check if the Widbox widget is added, press the "Preview" button and in the faded menu, click “Preview in new tab”.
Add widget to all pages
Log in to your WordPress website's admin panel.
Go to “Appearance” -> “Editor”.
Select “Template parts” in the provided menu.
In the provided menu click “Footer” button.
Click on the “Edit” button (a pencil icon) to enter the footer ”Editor mode”.
Editor mode:
Click on the “Plus” button (+) to add a new block.
Search for "html" in the blocks menu.
Click on the "Custom HTML" button that appears.
An empty HTML block will appear at the bottom of your footer.
Paste the Widbox HTML code (Ctrl + V) into it.
Use the arrows to move the HTML block to the desired position in your footer.
Click on “Save” in the top right corner to publish the Widbox widget for all pages.