International Competitions - Rule Changes

Hi everyone! I really need your help, because I've been trying to do this for a while now 😢 

The only thing I wanted was to change international squads from 23 man to 26 man, just like in the world cup. I've been trying to change that in the editor, but with no success. How can I do this? Thanks a lot 😉

easy to do explained here https://www.fmrte.com/forums/topic/9481-faqs-editor-how-to-guide-advanced-rule-editing/?do=findComment&comment=59707