Add fillable form fields and descriptions, and set the tab order

If your PDF includes form fields, use Advanced > Accessibility > Run Form Field Recognition to detect form fields and make them interactive (fillable).

Use the Forms tools to create fillable form fields, such as buttons, check boxes, pop-up menus, and text boxes. When you create a field, type a description in the Tooltip box in the Properties dialog box for that field. Screen readers read this text aloud to the user. For more information, see Create form fields.
You can also use the TouchUp Reading Order tool to add descriptions to form fields.

For information on setting the tab order to use document structure, see Set form field navigation.