Each YouTube channel has a unique user ID and channel ID. These IDs are used to refer to the channel in certain apps and services.
Find your channel's user ID & channel ID
You can see your channel's user and channel IDs in your advanced account settings on a computer or mobile browser.
Sign in to YouTube.
In the top right, select your profile picture > Settings.
From the left menu, select Advanced settings.
You’ll see your channel’s user and channel IDs.
You must be signed in as the channel's primary owner to see this info.