How to fit an image to the size of your button using xaml?

Hi,

I'm very new to Xamarin.Forms and XAML in general.

I'm currently doing a basic app where I want to have a button displayed as a barcode scanner image. However, the image I am using doesn't fit the button as it's too big and only shows a small portion of the image I want to use when using the HorizontalOptions property. When I'm not using the property, the button will expand to the real size of the image which is big.

Here's the code:

If you could help, that would be perfect.

Thanks.