This the tool for searching correct noc.I will provide you. Generally They don't help in any way. Also confuse.
https://www.canada.ca/en/immigration-refugees-citizenship/services/immigrate-canada/express-entry/become-candidate/eligibility/find-national-occupation-code.html
P.S. - I think noc 2173 can work. They will consider. Because they consider Mathematicians also.