Just to confirm, you’re trying to do this, right? https://dev.twitch.tv/docs/v5/guides/using-the-twitch-api#translating-from-user-names-to-user-ids
If so, the default version for api.twitch.tv is v3. You need to specify v5 in order to use the endpoint as shown above.
@Athreem please add the ‘Accept’ header with the following value to get a result:
application/vnd.twitchtv.v5+json
Thank you, tell me more please how to know the number of viewers and online stream?