" Not on your life" is a phrase used to mean that something is not going to happen, even if you kill me I'm not going to tell you.
“Not on your life” 是一个短语, 用来表示某事不会发生, 即使你杀了我我也不会告诉你。
英语百科
Not on Your Life
Not on Your Life is a 1963 Spanish black comedy film directed by Luis García Berlanga. Its original Spanish title is El Verdugo, which means "The Executioner". It is widely considered one of the masterpieces of Spanish cinema.