The Accordion widget requires a repeater field either on the current page, preview page(post etc) or on an option page. The supported subfields are text, textarea and wysiwyg.
You find it easiest by searching for ACF Accordion in the Elementor Search Widget … field:
Drag the following widget icon into your section to add the widget.
After adding the widget to your section/column the following settings are shown.
Field is a dropdown with the detected Repeater fields. When you select a repeater field the title and content fields will be shown. Accordion title and accordion content drop downs contain detected subfields.
You can style the whole accordion area, the title and the accordion content.
The most interesting options are if the accordion should be opened from the start or not and how it should behave when a visitor clicks on a title.
Page/post ACF fields
The accordion tab order is based on the order of the ACF fields in the repeater field on the edit page.