Hi Celia, yes it looks like the Windows version of FL Studio has a built-in way to Convert MIDI Notes to Sheet Music, using the feature Export as score sheet.. (available in the Piano Roll!)
Here's a very helpful Image-Line forum post about making sheet music in FL Studio:
https://forum.image-line.com/viewtopic.php?t=230896
There also seems to be another way of exporting all your different sounds and instruments into a MIDI File, which you can then import into the free MuseScore software to view and listen back!
DAWNLIGHT (very helpful Image-Line forum user) shares it like this:
Go Tools > Macros > Prepare for MIDI export
Then.. File > Export > MIDI file... on export dialog select "Pattern" as the "Project type", then export.
Let me know how it works out for you, or if you have a more specific question about this.
Staff