It is a right straightforward task to install and configure Pi-Hole on a QNAP NAS.
Click on Create, and seach for pihole
If you already (as me) has pihole installed, then click Cteate otherwise select download.
Enter a name for your Pihole installation, and edit how much RAM and CPU it must use.
Click on Advanced Settings, then select Network.
Change Network mode from NAT to Bridge
Use a static IP acording to network/DHCP setup
Click on OK
Our Pihole is now created.
Pihole is now installed and ready for use, but we don’t know the password for accessing the web site.
We therefore need to reset it by the terminal.
Click on Terminal as below.
Enter pihole -a -p
Enter a new password and press Enter
Password has now been set.
Open Pohole with the IP you configured earlier.