As the title of the question states, I would like to forward my iCloud email to my Gmail address. Specifically, I have an iCloud email that I made with my Apple ID as well as a Gmail address I made back in 2012 or something. Most of my emails go to my Gmail address, but I would still like to use my iCloud address for a few specific things. I know the easy answer is "go into your mail app and set up a filter to forward everything to your Gmail address," but the only Apple device I have is an iPhone and (as far as I can tell) you can't make filters from there.
Given this information, how can I forward all my iCloud email to my Gmail address?