According to James 1:5, if anyone lacks what, he should ask God, who gives generously?

Answer: Wisdom

If anyone lacks wisdom, he should ask God, who gives generously without finding fault, but he must ask in faith, without doubting.

“Now if any of you lacks wisdom, he should ask God, who gives generously to all without finding fault, and it will be given to him. But he must ask in faith, without doubting, because he who doubts is like a wave of the sea, blown and tossed by the wind.”— James 1:5-6 (BSB)