Hi there! 
It sounds like you’re wanting to have a list of just single kanji, and not study words? If so, you could create a custom list with only single kanji entries, and remove the lists that have the multi-kanji words in it (or ban the words as they come up for study).
I really do recommend not studying individual kanji by themselves, unless it’s a word on it’s own. Here’s a blog post about this: https://blog.skritter.com/2017/03/shouldnt-study-single-kanji-japanese-not-high-frequency-word/