How to clear caches on my iPhone 6 Plus

You can't clear the iPhone's total cache with the click of a button. iPhone does a pretty good job of that automatically. You have to go settings in different apps and clear cache that way if they have an option to. For example, I know TikTok does.

If you want to clear the total cache on your iPhone, back it up to iCloud then factory reset it and restore it. I've done this before and it really helps squash bugs and clear up storage. Note that backing it up to iCloud means you won't lose data.