I once raised a swallow that fell from its nest. I can pat a few flies to feed it, or buy a few Tenebrio molitor and cut it into two pieces to feed it. The effect is good.

Pay attention, just feed two or three drops of water every day, too much will cause diarrhea.

You can take a toothpick and put a fly or Tenebrio molitor on it, the mouth of Doby Swallow. Usually peck. If it doesn't work, open your mouth and feed it. After a long time, swallows will get used to it.

I hope you can feed it alive.