Click on [File -> Export Page(s) as HTML...] menu point.
The Export Wizard will display.
First you have to give you album a name (which will be used in the generated HTML).
Set the beginning and the end page which you want to export.
Click [Next]
Set the options for the page generation.
If you try this for the first time, just leave the settings as they are.
Checking the 'Include separate...' generates not only the page containing all the photos; but also a close up for each photo.
Click [Next]
Set the destination directory.
Introduce a photo copyright text.
Set the URL's which link to the pages before the first and after the last album page.
Click [Next]
Click [Go] and in the log window the progress of the generated files will be displyed.
(And be patient, this has not yet been optimized.)