Which is more suitable for fine lines around the mouth, Botox or fillers?

Lately, when I look closely in the mirror, I notice several fine lines next to the corners of my mouth, and I am concerned that my mouth area looks slightly droopy even when I am expressionless. The lines that used to only appear when I smiled now remain even after applying makeup, and they appear even more prominent as foundation settles into the wrinkles. I have consistently tried moisturizing and firming care at home, but since there doesn't seem to be much change in the fine lines around my mouth that have already formed, I am looking into Botox or filler treatments. I am curious if the appropriate treatment varies depending on whether the wrinkles are caused by facial muscles or by a loss of skin volume. I would also like to know if it is possible to manage the condition with only Botox or fillers, or if there are cases where both are administered together. What should I check during a consultation to make my mouth area look softer while maintaining a natural expression? I am also curious about when the effects will appear, the duration of the results, the recommended frequency, and the price per session. I am also concerned about bruising, swelling, potential discomfort when smiling or speaking, and the recovery period. I would like to start the treatment without overdoing it after receiving a thorough consultation on the methods and precautions suitable for my condition.