Custom Anchor Function

The custom anchor function is updated on trigger update and should return a frame.

This example paired with a "cast" trigger with unit = "player" will anchor the region to your target's nameplate

function()
    if aura_env.state.destUnit then
        return C_NamePlate.GetNamePlateForUnit(aura_env.state.destUnit)
    end
end

For dynamically anchoring multiple auras to multiple frames, refer to dynamic group Custom Grow Functions and Group by Frame