Hey @Mike29770612qgz6. Welcome to the Lightroom Community. I'll help you start masking in Lightroom mobile (iOS).
What specific devices & versions of Lightroom Mobile & iOS are you working on?
Here are a few tips before you go into the tutorials:
- Luminance & Color Range masking appears when you create a new mask. Just scroll down a bit.
- More Adjustment sliders are available when you scroll down once you generate a mask.
Some features like Select Subject and Select Sky in Masking are unavailable on older iOS devices. Check information about this & for more help getting started here: https://helpx.adobe.com/lightroom-cc/using/masking-mobile-ios.html
This should help. Thanks!