Hello,
Assuming you’re talking about simplified creation, rather than directly coding, when creating a new condition you first click on the relevant part of the chart, specifically in the window where the added indicator is, so that it can appear in the list.
For example if you’ve added your vwap as a separate window below the price rather than in the price window, it would appear in the list if you click on that vwap window, but clicking in the price window wouldn’t make the vwap appear in the list, even if you see your vwap in the window below.
If you need your vwap to be in the price window because your screener or backtest conditions make it interact with price or other items from this window, you have to go to top left corner click on “price” then “add indicator” and add your vwap there (rather than in separate window below). And then when using simplified creation of screener/backtest, it will be available in the list when clicking in the price window.