Hmm. Sounds like you may be using an old or non-standard browser? Twine should just work by default on Chrome or Chromium based browsers or firefox.
You could try downloading the desktop app at
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import the story and then hit the play button from the Build menu.
The choice macro has been deprecated in later versions of twine but it hasn't been removed so it should still function, and nobody else has reported this issue, so I assume it has to be something on your end. I can't replicate the issue on my local copy.