Is Basic different from Professional?  In Professional you can get the transaction to be reported with Box C.  Just answer "no" when asked if reported on Form 1099-B.

As for attaching their Form 8949, I would not do it.  I had a client with Coinbase in today and this is what I did.  I took the Excel spreadsheet and did a little reformatting.  It took less than 5 minutes to do.  I got rid of the columns with the worthless info, such as transaction ID, etc.  I moved everything down so I had room for a header where I added the client's name and SSN and a description "2022 Coinbase Short-Term Transactions Not Reported on Form 1099-B".  I formatted the purchase, sales, and gain columns to two decimal places.  Then at the bottom I totaled these columns with a column footer (Total Sales Price, Total Purchase Price, Net Gain/Loss) and attached this document as a pdf to the return.  On the Schedule D worksheet, for the description I put "Coinbase Transactions - See Attached", entered the total sales price and total cost basis, and made sure I checked "no" when asked if reported on Form 1099-B.  Since these were all short-term, for date sold I put "12/31/21" and for date acquired I put "Various", while indicating "S" for the holding period.