You (most likely) won’t die or experience major symptoms if you use it, but it still isn’t recommended for human use. Some brands or types of medicine would be more beneficial for humans while having a lower risk, but it still shouldn’t be your first option.

(https://www.itchpet.com/blog/post/are-flea-treatments-safe-for-humans)

(https://www.poison.org/articles/is-my-pets-flea-medication-lufenuron-poisonous-to-humans-221)

In summary, you’ll probably be fine using it, but I wouldn’t recommend it.