You can find your trading view user id under your Profile settings. There are a few ways to get to your profile settings. You can find both your user id and profile as follows: Log into TradingView. Select the options menu (the three horizontal lines - you can see that button just below the left arrow at the upper left) - it is provided at the upper left of a chart. You’ll see your user id appear in the menu that appears. In the following image, John O is the user id, shown in a red square in this screen capture.
To see your profile settings, hover over your userID to then select your Profile Settings. Your TradingView username (ID) will also appear at the top, and also in the Public Info section, in the field labeled, Username, as shown below, pointed to by the red arrow.