Install error

Platform:
Provider: Strato
URL: http://go-indonesia.asia/wp-admin/update.php?action=upload-theme
Database MySQL: 5.6.41
Installation
WP: Version 4.9.8 Installationfolder WordPress_07

When installing the themeforest-19029758-travelwp-traveltour-booking-wordpress-theme.zip using the admin dashboard the following error occured: the packet can not be installed. The theme doesn’t have a style.css stylesheet.

Theme installation failed.
Thats not what i want to see after paying 70 USD!!!!