Do you really mean that you purchased the 2021 software to download so that you can prepare a 2021 return to print and file by mail?
You need a full PC or Mac for the CD/download software. It cannot be used on a phone or any other kind of mobile device.
Access your downloads here
https://shop.turbotax.intuit.com/commerce/account/secure/login.jsp?pagecontext=download
https://ttlc.intuit.com/community/tax-topics/help/activating-turbotax-cd-download-software/00/852971
To find your license code:
https://ttlc.intuit.com/community/tax-topics/help/i-can-t-find-my-license-code/01/852973
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**