Help with theme installation

Hi everyone i'm new to this forum so I hope to do things correctly,

I'm trying to install a new wordpress theme i purchased two days ago but i can't get it to work on my site, the installation process starts but when it reaches 100% i get redirected to a page that says "error: this link has expired".

I looked around and apparently it's a problem related to the theme's size, so i tried modifying the .htaccess file on my dashboard by copying and pasting a code provided by the theme's developers ("The Newspaper") but no matter where i copy and paste it it just keeps giving me the same error.

I also tried searching for the .ini file but i can't locate it, nor can i create a new one because the panel does not include the .ini type among those you can use to create files.

Now i succesfully uploaded the theme in the wp-content folder in my file management section, so i have the theme's .zip file in the folder but when i use Wordpress to actually install it, i just can't find it so i tried again to upload it and install it from my computer but again i got the same expired link error.

What can I do?

Thanks