is supposed to be 10,000 per brokerage account. contact support
https://ttlc.intuit.com/turbotax-support/en-us/help-article/import-export-data-files/enter-large-num...
using a third party provider does nothing because the PDFs generated can not be attached to your e-filed return.
or enter summary totals, and e-file your return.
then mail form 8453 with the 1099-B following the instructions on the 8453 9tTurbotax should generate form 8453 which must be printed) when you indicate with M multiple trades are reported on various lines
https://www.irs.gov/pub/irs-pdf/f8453.pdf
