Transfering pokemon from old games to new, no poketransporter

Hi!

I haven't kept up to date with Nintendo news or thought about my Pokemon for the past years until it was brought to my attention that Pokemon Bank will be shutting down at the start of next year.

I could transfer my Pokemon Sun pokemon out easily, but I remembered having some older event pokemon that I traded to my Pokemon SoulSilver-copy. I would like them to not be lost forever, but based on my Google searches I'd need Poketransporter to do that. I thought I could download Poketransporter through Pokemon Bank, but that doesn't work (anymore?) since I never downloaded it before.

Am I missing a solution here or did I just run out of time?