Go to the Customizer -> Widgets. From this section, you can customize the widgets section with the specific widgets you need to place on your website.
Widgets in the footer section
To place widgets in the footer section, you have to first go to Footer Settings, and select a footer template that accepts widgets.
Then, to begin adding widgets, you have to go to the WordPress Admin dashboard -> Appearance -> Widgets.
Drag and drop from the list of available widgets, the ones that you want to place in each of the 3 footer widgets boxes: