I did a setup of PLUGIN: Manual (Fixed or By Weight) for rate computation but I cannot get Additional fixed cost as a shipping cost after some configurations. When i go to 2 step it says the shipping cost is 0. I went to "shipping rate computation method" and set Manual (Fixed or By Weight) as the only active method. Also this account doesn't have free shipping box checked. After i set fixed rate of shipping method different from 0 it gets as a shipping cost this rate. Is there something that I am missing? The same thing happens on the development and live.
Thank you in advance.