You can easily upload a backup of your website by opening your cPanel → File Manager:
And by following this procedure:
Select Upload option at the top-right corner of the File Manager window:
Choose the compressed file that you would like to restore:
NOTE:
You can also check the checkmark to overwrite any existing files
After the file has been successfully uploaded, right-click on it and select Extract:
Finally, select the extraction directory (in this example the files were extracted to public_html directory).
That’s it! You are ready to use your files at cPanel!
NOTES:
The maximum allowed size for uploading a file using File Manager is 256MB.
If you want to upload a bigger file, you can use an FTP client, as there are no size limitations for uploading files.