There isn’t any way to use an ACF image field without the images being uploaded to the media library. To do something like this you’d need to probably build your own custom field type to get images from a folder rather than the library https://www.advancedcustomfields.com/resources/creating-a-new-field-type/
You could possibly use a select field and dynamically load the field choices based on the images in a folder https://www.advancedcustomfields.com/resources/dynamically-populate-a-select-fields-choices/. This can also be used for a radio field. But I don’t know how you’d go about showing the images rather than the file names.
