Override template does not work

Hi,

I want to override the ‘thumbnails.php’ file. I have created a folder in my themes folder called ‘wp-car-manager’ and inside of that folder I have a ‘thumbnails.php’ file with my custom code however, this is not reflecting my changes.

I read the documentation and did exactly what it says but no luck. Can you guide my in the right direction please.

Many thanks,

Raj