将伽马混合物与R中的生育时间表相匹配

I am trying to fit a gamma mixture model (two gamma distributions) to an age-fertility profile. I have a dataset containing age specific fertility rates and age, and I want to fit two gammas in order to find the corresponding parameters (in the end I will use fertility profiles from different years and try to see how the parameters evolve over time). I have so far tried to use mixtools library (gammamixEM) but without success. I would be very grateful for some help.I am trying to fit a gamma mixture model (two g