Samsung Easy document Scanner won't communicate with scanner on OS X Catalina 10.15
That is because Easy Document Creator uses several apps underneath and not all are 64-bit, as required by Catalina.

One of them is Select Scanner.app (in /Applications/Samsung/Samsung Easy Document Creator.app/Contents/Resources/Select Scanner.app), which is 32-bit for Intel and PowerPC (!).

The other one, with the same problem, is ICCUpdater.

There's nothing you can do; only bug HP to publish updated version.

Meanwhile, to be able to scan at all, use Image Capture or Preview (File, Import...). Just make sure that the scanned file is OK, the Apple drivers seem to be broken too; for example, I cannot scan in color into PDF, the resulting PDF is broken (Samsung M2070w). B/W PDF is fine, so is color JPG.