Please refer to this article in order to see the updated method of getting the Instagram widget to work.
Can I display my Instagram posts within Elementor?
In Elementor you can showcase your Instagram feed using different layouts, display the tagged photos or the ones from the profile and style your Instagram feed with a powerful Instagram widget.
Note: Before adding Instagram widget to your layout, add the Instagram Access Token to the WordPress left menu > Elementor > Jet Elements Settings > Instagram Options > Access Token
You can read more about how to get Instagram Access Tokenhere.
In order to add Instagram element to your web page:
1. Add a new page or edit an existing one.
2. Click on Edit with Elementor button.
3. From the Elementor’s left dashboard, drag and drop the Instagram widget into your layout so that a new panel will open on the left side of the Elementor with the element’s specific settings.
4. Customize the widget and Update the settings.