First of all, it's not your email address!
You'll see your TradingView Username repeatedly as you use the TradingView platform, but its location changes slightly depending on what page you're on. You can always confirm you have the correct Username under your Profile settings. To get to your profile settings:
Log into TradingView.
Click the 3-lines option menu usually located at the top right after you log in - though it's at the top left if you're showing a chart. The three-line option menu might be an icon if you've set an icon image for your account - if so, click that, and select Profile settings (and by the way, your Username is the name that's shown at the top of the popup menu).
If you're already looking at a chart, you can also identify your Username when you Select the options menu (the three horizontal lines or an icon if you've set one - you can see that button just below the browser's back arrow button at the upper left) - it is provided at the upper left of a chart. You’ll see your username appear in the menu that pops up. Select Profile Settings, as highlighted with a red rectangle in the following image.
Once you're in your Profile Settings, look for the Username field, which shows your Username. By now, you should know your TradingView username, and confirmed that you have the correct one.