This would not be possible based on the best of my knowledge. There are options at the first 1-2 months of birth and really the first month when the ear cartilages are soft and susceptible to molding through products like Earwell. But to make your ears more pinned would require a small procedure. You wouldn't have to put totally out and it can be done under light safer anesthesia.
It is not possible to bring your ears permanently closer to your head without an operation. However, there are otoplasties of different degrees of invasiveness. The least invasive operation is the stitch method.
Unfortunately, there is not a non-surgical method to permanently push back the ears. Wearing a hat that covers at least the top of the ear or growing longer hair can sometimes help to hide the ears a bit so they don't look like they are sticking out as much.