Thanks @ottischwenk! My Note Pro 3.2.x doesn't have that setting in the library.
Support suggests that I should wait patiently until 3.3.1 is released for the Note Pro Android 9.
So another approach would be to just install the apk of the library and hope that the sync function is implemented. However, don't see a likely candidate. I see a
ksync.apk in the
ksync-release directory, though. Anyone know how this part of Onyx software ecology works?