In current French mathematical tradition, when introducing complex numbers, it is common to hear about "complex plane of Argand-Cauchy". What is particular in French treatment, it is the differentiation between the geometric objects of a "complex plane" and complex numbers: complex numbers are complex coordinates of vectors and points of a complex plane. To each vector and each point of a complex plane, the French associate a complex number, called their affixe (probably this would read affix in English).
I tried to find the origin of the term "affixe" and that of the French treatment of the geometry of complex numbers in the literature but failed so far. I've looked through the essays of Caspar Wessel and of Jean-Robert Argand, but they do not use "affixes", and they could not, because for them complex numbers were vectors.
Who, when, and how used the term affixe/affix for the first time? Same question about differentiating between complex numbers and their geometric realisations.