Fumoto valve levers sometimes get a little stiff in shipping.
Using the middle of your thumb (right on the digit) to lift and push the valve lever with some force will always solve this issue.
There's no need to use a hammer or any other tool. Your thumb and some pressure will do.
Some valves will need a little more pressure than others. In this instance, don't be shy with the valve lever. It's tough as heck and can take a little thumb wrestling with ease.