jota, thanks for your reply. I'm very grateful.
I have never used bitnami or MediaWiki before. I am a complete newby on this. I downloaded the bitnami stack, 1.32.2, and am beginning to develop a wiki site on my desktop on the local host, I guess. I hit into a snag when I tried to follow the citation procedures, which were introduced (the help pages say) in 1.25 or so. I then looked at what version I have running and it states it to be 1.0.3. Which seems bizarre. Is it possible to send a screenshot of that to you, to confirm I am correct? Nevertheless the bitnami app package for MediaWiki does include what appear to be the latest extensions, including for CiteThisPage. I'm at a loss!