Got Uncaught (in promise) DOMException in demo

[JayGuAtGitHub]

I test the demo code and failed. Then I tried the demo at the link as below:
https://hackingbeauty.github.io/react-mic/
and I failed again.

For both I get the same exception:

(index):1 Uncaught (in promise) DOMException
Promise.then (async)
startRecording @ MicrophoneRecorder.js:58
t.render @ ReactMic.js:98
u @ react-dom.production.min.js:129
beginWork @ react-dom.production.min.js:133
o @ react-dom.production.min.js:160
a @ react-dom.production.min.js:160
i @ react-dom.production.min.js:161
x @ react-dom.production.min.js:167
k @ react-dom.production.min.js:167
batchedUpdates @ react-dom.production.min.js:170
st @ react-dom.production.min.js:53
Jt @ react-dom.production.min.js:70

I saw someone saied it was a https problem, however I think I tried .github.io link with chrome so it should be another problem.

[JayGuAtGitHub]

I got the reason, I didn't put the audio input device... so...