You may also use uman() (from https://atoms.scilab.org/toolboxes/uman)
with its w option: Then you will always target the online help version of
your current Scilab version, without external search engine, which
by the way is an energy-saving solution.
A version of uman() making it able to display the local HTML help pages
in the web browser is in preparation.
But of course, anyway, for it, Scilab needs to be running.