encryption passphrase

So I started using the Brave Browser on my iPhone (SE second gen). It is free, but does come with ads. I do not click on them often, but one did pique my interest and in doing so, I ended up going to an ad that was about crypto and needing to add an app then my Apple wallet (that I had deleted :(, that I never use and my "enter your iCloud encryption passphrase". Really? exactly what is that? That does not seem to be the same as my iCloud password, by what I researched on the web. If I have "lost" it and I "remake" it, I will basically be taking my phone back to factory-set, correct? Is there a way to find this passphrase? Thanks,

Answer4mePlz