If you bought or downloaded a premium WordPress theme, you’ll need to install it via the upload option from your WordPress dashboard.
Have you already downloaded the premium theme you intend to install? if not, download the theme from the Envato WordPress theme marketplace or website where you saw it. It is usually a .ZIP file.
Note: If it is a .RAR file, you’d first need to extract the .ZIP file before uploading it to your WordPress. Most themes come in .ZIP files, so you might not need to worry.
From your WordPress dashboard, go to Appearance > Themes and click Add New:
TIP: Make sure that you are installing a .ZIP file and not a .RAR file. If you had downloaded a .RAR file, you would need to extract the .ZIP file inside it for uploading to WordPress.
Next, click Upload Theme button to upload the ZIP file to your website from your computer:
Click Browse to select the zip file from your computer.