Or you could scan it to create a pdf and use the (often not very good) Import pdf facility (located in the File menu) to create an xml file that can be opened in musescore. But, depending on the complexity of your starting sheet music and the quality of your scan, be prepared to make many corrections. And making those corrections is likely to be more complicated than just entering the music by hand.
Comments
Read the printed music and use the editing facilities in Musescore to create a score - see https://handbook.musescore.org/introduction/create-your-first-score
Or you could scan it to create a pdf and use the (often not very good) Import pdf facility (located in the File menu) to create an xml file that can be opened in musescore. But, depending on the complexity of your starting sheet music and the quality of your scan, be prepared to make many corrections. And making those corrections is likely to be more complicated than just entering the music by hand.
https://musescore.org/fr/node/332696