Using a StackLayout requires the StackLayout module. {%snippet stack-layout-require%}

<Page>
  <StackLayout orientation="horizontal">
    <Label text="This is Label 1" />
  </StackLayout>
</Page>

{%snippet stack-layout-new%}

{%snippet stack-layout-addchild%}

{%snippet stack-layout-remove%}

{%snippet stack-layout-horizontal%}