How to install calendar app?

I am running Owncloud 8 on a QNAP system. I've got it running but I cannot figure out how to install the calendar app. It's here

but how do I get it added to my Owncloud installation?


which oC version is running on your NAS? (8 is not exact enough as there is 8.0, 8.1 and 8.2 as major versions).

It's running 8.0.4


the linked app is explicitly stating:

Minimum required ownCloud 8.1
Maximum required ownCloud 8.2

As 8.0.4 is outdated (you're currently missing 12 updates as 8.0.16 was the latest version of this branch) and unsupported since the last month i'm closing here. Please upgrade to oC 8.1 or higher. A few info about this is available here:

Please get in touch with the QNAP support for more support.