Apple Smart Keyboard for the 10.5-inch iPad Pro
The official Apple Smart Keyboard for the 10.5-inch iPad Pro is more expensive than the Logitech option, but it is also slimmer.
One downside compared to the Logitech is that the keyboard isn't detachable while still keeping some kind of case on your iPad Pro.
This attaches with magnets and a physical connection, so you don't need to charge the keyboard. It's a very slim option and it allows you to remain very mobile. There is no loop to store the Apple Pencil.
$159 at Apple