Guide for Asuswrt-merlin users with screenshots (forcing all traffic to Pi-hole) : r/pihole
ASUSWRT | ASUS Česká republika
ASUS RT-AC1900U Router Estendibile, Dual-Cpu Plug-N-Play, Asuswrt Graphic Interface, 5 Gigabit Port, Twin USB 3.0 For Storage Printer Media Server 3G/4G 90Ig04K0-Bo3000 : Amazon.it: Informatica
Enable port forwarding for ASUSWRT-Merlin - cFos Software