I have a sore or the left side of my right foot. it is below the ankle. it looks like an ulcer. i just noticed it yesterday. i have put topical antibiotic on it. i have a picture. do i need to be seen?

Yes you need to seen as soon as possible to why you developed this “ulcer “ Ulcer to the lower extremities are serious. See your family doctor immediately and a podiatrist to help with the ulcer care

Always a good idea, specifically in the context of having no explanation for its appearance, such as trauma/ pressure, etc. Starting with your primary care doc will be best.