Does expiation become obligatory for one who intentionally breaks their fast in Ramadan with unlawful acts such as "masturbation and smoking"?

What you used to do, intentionally breaking your fast in Ramadan, is a great sin, and it is one of the major sins. What is obligatory is to repent to Allah Almighty and make up all the days you broke your fast, because they are a debt upon you, based on the Prophet’s (peace be upon him) saying: "Allah's debt is more worthy of being fulfilled." You are not required to offer expiation (kaffarah), for it is only obligatory for breaking the fast through sexual intercourse, according to the more preponderant opinion.