The channelId query param expects the unique identifier provided to the channel by the host platform - for example, the expected channelId value for a YouTube channel would be the variable-character string value prefixed with a UC string which YouTube assigns each channel upon creation. The YouTube channelId is only displayed publicly on youtube urls that contain the channel resource like: youtube.com/channel/<channel id>.

The channel name usually maps closely with “user name” or simply just the ‘name’ of the channel. In the YouTube example, this would be any string value following the youtube.com/ or youtube.com/c/ url strings.