Couldn't work screenshot (Alt+1, Alt+3) in web app
as is: 
  Alt + 1 or Alt + 3 cause freeze in web app.

to be:
  I want to download screenshot pictures.

environment:
  [https://kitao.github.io/pyxel/wasm/examples/script_test.html](https://kitao.github.io/pyxel/wasm/examples/script_test.html) and others.
  -Microsoft Edge or Firefox
  -Windows11