Populate dropdown with ACF (custom field) options

We have a dropdown that was created in ACF. It has numerous dropdown options that were built in ACF. It’s not a “taxonomy” though. How would we be able to populate the Gravity Form dropdown/customfield options from this ACF field?

If I choose a Drop Down element, it wants me to populate with Taxonomy (not custom fields). If I instead choose the Custom Field element (and set the field type to dropdown), there is no option to have it populate the choices with the custom field’s options.