Installing Themes in WordPress

Recently purchased ‘Tumber’ and have an error message when installing in WordPress…
"The package could not be installed. The theme is missing the style.css stylesheet”.
If anyone can help me with this problem, it would be much appreciated.
I am using WordPress version 6.7.2

Template Details
Author: Colorlib
Released: August 2022
License: CC BY 3.0
Credits: Images from Unsplash