hi there Dmitry and thanks very much for the reply. As I stated above:
I know how to install the package. That, however does nothing towards explaining to a user what to do next, that being how to access it from the web. When you used the owncloud setup script, you knew to visit that directory to log in. What do you do after an apt install owncloud?
You install ownCloud on a server, right? this server has an IP address.
if you have installed ownCloud, configured your apache server and have the right php modules (LAMP) then you can visit ownCloud by typing your server’s ip in a browser and adding /owncloud
It seems a little shortsighted to think that owncloud servers would be systems that only one person/group would be using and that the installer might not want it accessible across all the domains / web accounts installed on that server.
okay, either you have a concrete question to a part of the documentation, that we can discuss and add to the existing one, or you can try to implement what I have written or look for a solution in this forum, where users help other users.
You asked - what to do after apt install. I answered : ip/owncloud