How to Find a YouTube Channel ID for Custom URLs

If the YouTube channel uses a custom URL (like https://www.youtube.com/c/ChannelName or https://www.youtube.com/user/ChannelName), follow these steps to find the channel ID:

1. Open the channel's YouTube page.
2. Right-click on the page and select View Page Source.
3. Use Ctrl + F (or Command + F on Mac) to open the search box in the page source.
4. Search for a string that starts with UC. It typically appears in a line like: "externalId":"UCXXXXXXXXXXXXXXXXXXXXXXXXX".
5. The string following "externalId": is the channel ID.