Adding button to list row

I tried to add button to each row if a list by referring to this doc:

and adding this code:

    button: {
        show(doc) {
            return doc.reference_name;
        get_label() {
            return 'View';
        get_description(doc) {
            return __('View {0}', [`${doc.reference_type} ${doc.reference_name}`])
        action(doc) {
            frappe.set_route('Form', doc.reference_type, doc.reference_name);

But I don’t understand what the doc.reference_name and doc.reference_type refer to.
Can some one please explain this?
Thank you

Got it.
Change those parameters according to relevant data.
And add add_fields to fetch the required field data.