A hole in the back of chicken neck

[HollowOfWisps]

Ok so I can try to use super glue to close the wound?

Yes, super glue is used even on people for closing wounds in emergency situations where you do not have access to stitches or steri-strips.

 

[coach723]

If it's leaking fluids and food, then the crop is also punctured. To correctly repair this requires two repairs, the crop itself and the skin over the crop, so two repairs so that you don't adhere the crop to the skin. If you only fix the skin, then the crop will still leak under it and cause infection. You will need to make an incision in the skin so you can see the crop damage. Flush it all out well with sterile saline or a chlorhexidine solution (hibiclens). You can use super glue to hold the damage if it's not torn too badly. After repairing the crop, make sure you have flushed out under the skin so that no food or debris is closed in there that may have leaked. Then you can do the same repair on the skin, making sure you don't adhere the two layers together. A gel type glue is better than a liquid, so it stays where you put it better.
There is a video here on a crop surgery, it's graphic if you are sensitive. If it's to much for you then vet care would be the best option.

This thread discusses sutures, if you go that route. Any sutures on the crop would need to be absorb-able, the ones on the skin could be removable.
https://www.backyardchickens.com/threads/what-suture-type-for-crop-surgery.1384783/#post-22744354