You upload your PDF to the MuseScore website. Under the hood, this service typically uses Audiveris , an open-source OMR engine, to analyze the notation.
The most direct way to convert your files online is through the official MuseScore PDF Import tool . pdf to mscz converter online
A highly regarded app that can instantly convert photos or PDFs into MusicXML with high accuracy, even for complex piano scores. You upload your PDF to the MuseScore website