" To have your fingers crossed" (crossed) means that you are hoping, you are praying, you're not sure and we use that expression when you don't have any more control over what will happen.

“To have your fingers crossed” （交叉）意味着你在希望，你在祈祷，你不确定，当你无法控制将要发生的事情时， 我们会使用这种表达方式。