Using 2021 product, how to import 2021 transacitons?

Sorry ... it is too late to import any prior year infomation from any source.  All you can do is manually enter the required information.  

How to enter a summary in lieu of individual transactions

Your brokerage statements should include a summary of your transactions, grouped by sales category, for example "Box A short-term covered" or "Box D long-term covered". You'll enter the summary info instead of each individual transaction.

1.  Search for stock sales in the search box.
2. Click or tap the "Jump to" link in the search results.
3. Answer Yes to both Did you sell any investments? and Did you get a 1099-B?
   • If you land on Here's the investment sales info we have so far, select Add More Sales. Then answer Yes to Did you get a 1099-B?
4. On the Choose Your Bank or Brokerage import screen, select I'll type it in myself.
5. Select or enter your brokerage on the next screen and continue.
6. On the following screen (Tell us about...) select the second option, I'll enter a summary.
7. On the same screen, enter the total proceeds (sales) and cost basis, along with the sales category. Refer to your 1099-B for the amounts and category. When finished, select Done.
8. Follow the onscreen instructions to enter additional sales or to view a summary.

When you are done entering all your sales transactions, you'll eventually come to the Here's the investment sales info we have so far screen. Here you can edit, delete, or enter more sales.

Sorry but imports for 2021 is closed.   Only the current tax year (2022) can be imported when they become available.   When they become available is up to the financial institution that supplied the data - usually Feb to March.