Welcome @kathiev, I suppose it might depend on the specific essential oil. It's been quite awhile since I've used essential oils but I always used a carrier oil since it was recommended to me not to use them without using a carrier oil.

"People make essential oils through the distillation of the aromatic leaves, flowers, barks, and roots of plants. If they apply these oils directly to the skin, however, they can cause reactions, such as severe irritation, flushing, or burning. Carrier oils dilute the essential oils and help “carry” them into the skin."
-- What is a carrier oil? Best oils and uses: https://www.medicalnewstoday.com/articles/321639

Have you read something that said to use the essential oil without a carrier?