Downloading Previous Version UE4

So I’m trying out UE4 and I want to also try a few different packages with the engine, that require v4.14 or 4.16.
I’m using 4.21 right now.

I’ve read that to install a secondary version you can just go to the launcher and pick and download a different version. But I can’t find where. No other version seems to appear from the drop down/list? I’ve read that exiting and reopening the Epic launcher can fix that, which I’ve tried, but still no other options.

I’ve also heard from another source that you can use previous packages with newer versions of UE but not newer version packages with older versions of UE. Yet the store packs say they can only be downloaded/opened with a previous version…