Hi @louiswalch
Could you please make sure that $_POST['acf']['field_582e2b81527b6']
has the correct value? If it’s, then you can update the field like this:
update_field('field_582e2b81527b6', $_POST['acf']['field_582e2b81527b6'], 'user_' . $customer_id);
This page should give you more idea about it: https://www.advancedcustomfields.com/resources/update_field/.
I hope this helps 🙂