so I am not a fan of tiny sd cards so I wanted to use full-size cards and so I searched Thingiverse and I did not see one for the Ender 3 Pro so I made one
I used Cura for my slicer

here is the reader I used https://www.amazon.com/gp/product/B06X3Y4BBB/ref=as_li_ss_tl?ie=UTF8&psc=1&linkCode=sl1&tag=patricksworks-20&linkId=cd67ff6a635de80dbf234c16ab8a4e0d&language=en_US