"In function of" existe no inglês?

Hello guys I have a very old question and today I remembered about it, I unadvisedly already use this structure, for example let me create a sentence very simples to make more clearer the sense of the expression I mean

Let's suppose someone says:

She does no want to lose her classes in function of the complexity of what she's been studying

I made a research on this matter and I found in the dictionaries the existence of "as a function of" which is different of "in function of"

Can someone help me? I will be very grateful, thanks!