No0b question from an FG veteran

[Milke]

As the title says. This may sound odd to ask. But when I have the monsters/bestiaries tab open, I can click an arrow that says "import monster", similar to the characters tab, I imagine.
I clicked on it, and it took me to my files tab of my computer.
So, my question is, what kind of file is it looking for? A json? A .txt? I've never done it.

[Trenloe]

That's looking for a FG XML file. You can export an individual NPC record to XML by opening the record and then right-click -> Export Record.