Hosted version returns strangeness...

[bertrandgorge]

Here's the returned JSON from the API I got....:

{
	"status": "success",
	"url": "https://youtube.com/watch?v=CjyaQx0y8l4",
	"length": 55,
	"segments": 1,
	"transcript": "0:{\"a\":\"$@1\",\"f\":\"\",\"b\":\"i-dEv7N7_G2B1apWtEAsb\"} 1:null"  
},

[e-orlov]

same here

[bertrandgorge]

BTW, after investigating it's just that this API, like many others, suffers from Youtube's restrictions. The easieast is either to pay for a robust API or to use yt-dlp localy and then upload the transcripts elsewhere.