Zend certified PHP/Magento developer

Magento 2.4.3 CMS Page custom layout update

I am trying with no luck to update a layout to a specific page only to our magento 2.4.3 store.

CMS Page url key is:

product-finder

I have created in child theme folder this xml file:

app/design/frontend/MyVendor/child_theme/Magento_Cms/layout/cms_page_view_selectable_ product-finder_ProductFinderlayout.xml

just like magento docs suggest. Inside Magento_Cms folder as I want a CMS Page to update only.

Cleared caches but in admin in product-finder CMS Page there is no Custom Layout Update option in dropdown.

What I do wrong please?