I just tried Apple Cash on my phone, @neil. There is a button in iOS to email your Apple Cash statement which is a lame multi-page PDF. (This seems to be a known, unfortunate, and embarrassingly short-sighted limitation of the tooling. Perhaps someone can create a workflow to render the PDF to CSV data. 
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As @heather said, I believe the story is different for Apple Card (which I don’t have available for testing). I hashed out the workflow and column mapping with founder @peter about a year ago. The instructions should be available in the Import CSV Line Items workflow sidebar. Let me know if you run into any issues.