The RoonServer QPKG is not the same as the Roon Server software which is not included in the package (QNAP App).
Install the RoonServer QPKG from the App Center to use the Roon Server production branch or use the respective installers from RoonOnNAS.org to use the earlyaccess or the 1.8_legacy branch. It doesn’t matter that the production version from the App Center is the oldest one.
Was always available since the release of Roon 2.0 (and even before).