How do you make petn?

Petn, or pentaerythritol tetranitrate, is a highly sensitive explosive and its production involves hazardous chemicals and processes that are not suitable for non-professionals. Due to safety and legal concerns, detailed instructions on making explosives are not provided and should not be attempted. It's crucial to emphasize that handling or attempting to create explosives without proper training and authorization is illegal and extremely dangerous. Always prioritize safety and follow the law.