i tried to download turbo basic which i bought but there's no place to enter installation key
I'm sorry you are having download issues.
Can you please uninstall the original version, reboot your computer and use this link to download: https://turbotax.intuit.ca/product/download/index.jsp . It will prompt you for the IKC (21digits).
Furthermore, (if needed) please feel free to call our support team for personal assistance following instructions below: