Just add a microservo to the build. You can see and customize the releaser here: https://cad.onshape.com/documents/a2fad6d0cf64304307fcdafe/w/76f1b029aa6d6f58a28d5f7e/e/e2aaab103ed4d49d56a2d02a
The wishbang you can see on the picture it's from Jeremy Boswell: https://www.printables.com/model/274586-whisbang-rc-whistling-bombs
The author marked this model as their own original creation.