Hi @Carla_Perez_Mon,
The best approach would be to follow the general approach outlined here to construct your own classifier.
You can choose which steps you'd like to keep/skip and the order in which you lke to run them. For example, if I want to make an amplicon specific classifier (you do not have to; but it does help if you do not have enough memory on your machine to construct a classifier) I often follow this approach.