Updating instructions are:
Choose Help - Check for Updates to check manually.
or
To access this command…
Choose Tools - Options - LibreOffice - Online Update
However, in LibreOffice Version: 5.2.7.2, Build ID: 1:5.2.7-1+deb9u11
CPU Threads: 2; OS Version: Linux 4.9; UI Render: default; VCL: gtk3;
Locale: en-US (en_US.UTF-8); Calc: group,
The corresponding commands are not to be found. How to update?