What did Thomas want to do to believe Jesus had risen?

Answer: Touch his wounds

Thomas said, 'Unless I see the nail marks and put my finger where the nails were, I will not believe.'

“So the other disciples told him, “We have seen the Lord!” But he replied, “Unless I see the nail marks in His hands, and put my finger where the nails have been, and put my hand into His side, I will never believe.””— John 20:25 (BSB)