Bicycle chains generally have two kinds of buckles. One is to put a pin in it and bend it. Just straighten the bend and pull it out from the other end, and you can pull out the bolt.

The other one is clamped by a clamping pin, with an opening on one side and a fishtail shape, and the other side is curved. When the screwdriver is pressed on the two tips at the fishtail end, it will pop up, and then the pin can be removed.