See this TurboTax support FAQ for My Docs - https://ttlc.intuit.com/turbotax-support/en-us/help-article/import-export-data-files/upload-document...
Or are you referring to importing a tax form such as a W-2 or a Form 1099? If so, see these TurboTax support FAQs -
https://ttlc.intuit.com/turbotax-support/en-us/help-article/import-export-data-files/import-enter-w-...
https://ttlc.intuit.com/turbotax-support/en-us/help-article/import-export-data-files/import-1099s/L2...
