I have downloaded the Italian Dictionary Extension for occasional use. Where do I put it and how do I call it up when required. My normal language is English (UK). I cannot find anything in Help
Given that you are on Windows: note that the installer already has all dictionaries inside. You only need to make sure it installed the needed ones (by default, it decides what to install, based on your system language). Just use custom installation, and choose the needed dictionaries. This would make you not need any extensions (unless you know that specifically that extension is somehow better than the bundled one).
I re-ran the Libre Office installer, chose Modify > Optional components > Dictionaries. Then saw note “This feature will not be available”