It turns out the tax file format is not public and appears not to be xml but encoded in some fashion.
So the best way to handle this is to go back to the 2021 turbotax, and print return for records with all forms and calculation worksheets. In the list of forms you will find a capital loss carryover and a a federal carryover worksheet, of many pages dealing first with state and local income taxes, then other tax and income info, Excess contributions, loss and expense carryovers, credit carryovers other carryovers charitable contribution carryovers, qualified business sec 199 carryovers Then the question is how to enter these in H&R block.
