Good evening Papimouzo,
To transcribe a score into another key, you first have to rewrite the entire score and only then transpose it into another key...
It takes a lot of time, patience and care, and above all, a few hours of hard work...
Alternatively, there are paying software packages such as Photoscore and many others that allow you to have the score in digital format (musicXml, midi, etc...), but you still need to be able to read it (there are sometimes reading errors)... But here again, you need to put your hand in your pocket, as it's expensive...
Musically aristo08000