Error on installing WordPress theme

When i try to install BUENO theme on Wordpress i get error:

The package could not be installed. The style.css stylesheet doesn’t contain a valid theme header.

Theme installation failed.

Also the ZIP file that i downloaded has no index.php file in it.

And i have purchase licence for this site,

Can you help me, pls

Hi There,

Thanks for reaching out to us.

Unfortunately, I’m afraid BUENO is not a wordpress theme but a HTMl template.

Apologies for the inconvenience.

LoL, does this HTML template have backend? Admin page?
Where can i see the documentation about this themplate

Hello Adelcevski

Sorry but no, HTML templates do not have backend, you have to build them or you have to recreate them in existing WordPress themes