There’s a form here which when submitted will return a .dat file (which is just a text file in this case) when the “Dst Output” button is selected with either of the two subselects to it (I’m using “IAGA2002-like format”). The various “Start Year” and “End Year” fields must also be filled in (weird form, I know). I’ve looked over a lot of different posts and answers about how to use cURL with forms, but I struggle to understand how it would actually work for a form like this; I imagine it can’t be that complicated.