Anyone knows how to create a custom opportunity

This might be a much better question for the TS3 mod creation board on ModTheSims. :)

Yes I have searched there but those questions were like 8 years ago... I need a fresh tutorial for it. Might nraas have it, I might search there too

Nothing there too

I meant that this might be a better question to ask on the forum board. It is still active over there. The most recent two posts were from yesterday morning, so I don't know where the 8 years old thing was coming from.

I suspect at the very least that a working knowledge of programming in C++ will be required, although I believe that I have seen custom career specific opps designed by those who claim to not know the scripting language.