If you are looking for the trial version or cannot access the portal, you often need to locate the direct link. Tableau usually archives these. You can search the Tableau Knowledge Base for "Tableau Desktop 2021.4 installer" or use a direct link structure (often found in Tableau's "Product Downloads" archive page).
Tableau Desktop 2021.4 offers a range of new features and improvements, including: tableau desktop 20214 download install