iOS - Forms - XAML : How do I set the width and height of a view ?(Label, Button, ..)

In the xaml code below, how do I make Label and Entry occupy a certain width and height ? (in % of the screen or pixels)
At the moment, the width of Entry depends on how long the text in Label is.
More generally: Is there a document that shows ALL the properties of the views with ALL the possible values?

<StackLayout Spacing="2" HorizontalOptions="CenterAndExpand" VerticalOptions="Start" Padding="20" >
            
    <Label x:Name="appId" 
 Text="Hello"
   TextColor="Blue"
   BackgroundColor="Yellow" />

    <Entry x:Name="code" />
    
</StackLayout>


Thank you