No add new (theme) button - why is this not better explained

I just a domain via GoDaddy and the a themeforest them called Houzillo via Envato. Now I dont know how to install it because wordpress keeps saying I must use the 'Add new" (theme) button but there is none. I wish this would be better explained. I am so frustrated - hours later - no solution. Please help.

Hi,

Contact with your purchase item author @amentotech right here as a comments
https://themeforest.net/item/houzillo-bookings-and-rental-wordpress-theme/26114920/comments

hope they will helped!