How to add pi.hole to /etc/hosts

Well first I need to describe my actual config:

I have installed pihole on a docker ( MacVLAN to use port 80; I use 192.168.1.3 as IP for this docker) that works very well for all the LAN and all PC and devices.

I configure pihole not only as a DNS Server, I configure as DHCP server too.

My NAS have IP 192.168.1.4 255.255.255.0 and use as DNS Server 8.8.8.8 (configured in OMV WebGUI), this is because if use 192.168.1.3 that is the IP of my pihole DNS Server I have some errors on OMV boot (probably due OMV need to resolve DNS and docker still is not ready).

So actual config works well except that my NAS can't resolve http://pi.hole or http://pihole because I use google DNS in OMV

I want to add 192.168.1.3 pi.hole to /etc/hosts but file says:

# This configuration file is auto-generated.
# WARNING: Do not edit this file, your changes will be lost.
127.0.0.1 localhost
127.0.1.1 PDNS.local PDNS


# The following lines are desirable for IPv6 capable hosts
::1     ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
ff02::3 ip6-allhosts


192.168.1.4 PDNS.local PDNS

So my question is:

how to add line 192.168.1.3 pi.hole so my NAS (PDNS) know to resolve pihole address without lose on reboots / updates?.

Quote from geaves

Isn't this 192.168.1.4 PDNS.local PDNS auto generated from the network in OMV's GUI.

NO, PDNS is the name of my NAS and is well resolved, the only not resolved is pi.hole if I try to use from PDNS if I try to use from a normal PC works fine ( because PC are DHCP and use 192.168.1.3 as DNS resolver).

So my question is: how to add line 192.168.1.3 pi.hole PIHOLE so my NAS (PDNS) know to resolve pihole address without lose on reboots / updates?