To understand the "why" and "how" of this conversion, one must first look at the two formats involved: XML (Extensible Markup Language):
APKG is a compressed archive (essentially a ZIP file) containing: xml to apkg
If you aren't comfortable with coding, there are specific third-party tools designed to handle this bridge, particularly for common XML sources like Brainyoo or older flashcard apps. To understand the "why" and "how" of this