Mask to Below

[Gulfcoast]

I'm following a tutorial that calls for a "mask to below" on a curves layer but cannot seem to find that command. Any help would be appreciated. Thank you. 

[Alfred]

Welcome to the Serif Affinity Forums, @Gulfcoast.

You can’t find that command because it doesn’t exist in the iPad versions of the Affinity apps! You need to drag the masking layer in the Layers Studio and drop it onto the thumbnail of the target layer.