What Should I Call My Professor?
Snip:
Doctor
Anyone who has earned a doctoral degree can be addressed as Dr. Last Name. The most common doctoral degree is a PhD, but you might also encounter instructors with other doctoral degrees such as a Doctor of Theology (DTh), Doctor of Public Health (DrPH), or Doctor of Engineering (DEng).
When in doubt, Dr. Last Name is the safest way to address an academic you dont know anything about. It is generally the standard form of address for instructors who do not hold the rank of professor such as lecturers, readers, senior lecturers, and research associates.
While the titles of Dr. and Professor often overlap, they are not always interchangeable. Not all professors have PhDs. In fine arts, social work, and law, many professors will have an MFA, MSW, or JD (respectively) rather than a doctoral degree. And although some professors might also be doctors, Professor is a higher rank and thus tends to be preferred.
https://academicpositions.com/career-advice/what-should-i-call-my-professor#:~:text=Anyone%20who%20has%20earned%20a,When%20in%20doubt%2C%20%E2%80%9CDr.