Cancel subscription

Hi, I am travelling for 3-4months outside of Netherlands from november 2023 and i want to cancel my subscription for this period! I do not have a contract and only paying monthly internet/call subscription. I can’t find any option on the app to do this NOR find any chat support, stuck in a loop of automated responses on a working hours. Please help. 
 

I understand there is 1 month notice before ending the subscription. This is my 1 month notice. And hoping to have my subscription cancelled by 5th or 6th of November.