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You could try the audiveris program (which is free), I've heard some doable stories from ScanScore as well, if you don't mind paying up.

But even then, Optical Music Recognition (OMR) is still a fairly new and experimental thing. It quite often gets things wrong and if you're not yet familiar with your notation software, correcting these errors may turn out to be harder than simply entering the score yourself directly.

There is a rudimentary audiveris webservice offered at https://musescore.com/import, but as you have no control over the parameters, it really is a hit-or-(more-often)-miss scenario.

Updating to Catalina and the ability to upload a PDF are not related to one another in any form or shape.