How to customize rating bar size in xamarin forms

I used This XFControls plugin to create Rating bar in my app but This bar is too large in phones and i want to customize its size
I tried witdth request but it didn't work for me

xmlns:Rating="clr-namespace:AsNum.XFControls;assembly=AsNum.XFControls"

my xaml

     <Rating:RatingBar BackgroundColor="SeaGreen"

                                        StarCount="5" Step="0.5"  SelectedColor="Orange"
                                                       HeightRequest="40" HorizontalOptions="Fill" UnSelectedColor="LightGray" Rate="{Binding Rating,Mode=TwoWay}">

                                        </Rating:RatingBar>

how can i do that ?