OK, I need to study it more carefully. By the way great thanks for your patients 
https://docs.juce.com/master/classdsp_1_1FFT.html#a741278c596a0f050c7ba3aa496aae89f
After the transformation, you get floats of the FFT values with the real and complex parts interleaved. So of course, you can’t see any imaginary part when looking at the raw values, because everything is float. One value describes the real-part the next one the complex part. You have to interpret both as one complex value, and apply your processing (phase rotation) to both values (complex math).
Let’s say: Those together with the real parts create the phases. But I am sure you wanted to say that 
Thanks. Edited my response.
Hello,
great thanks for your patient. Yes, you are totally right. I checked all that theory, and finally it works. Thanks.