RB960PGS plus Pihole

Hello
I have joined a new ISP and have now installed my own Mikrotik hardware (same as ISP had supplied, rb960pgs + 2 cAPacs). The ISP installed + setup the connection for me. Before the change over I used to have Rpi with pi-hole and Fritzbox router.
The change over means a hole new game :-}
At the moment I have installed the Pihole on the Rpi4 and given a static IP and imported the last working config (I had setup with previous ISP). Proton VPN is also installed on the Rpi though like to work on that at a later date.

Default gateway: 192.168.XXX.X, DNS by ISP 103.XXX.XX.XX , 8.8.8.8
Rpi 192.168.XXX.XX(outside of DHCP lease)
Main working machine: Lan 192.168.XXX.X Wlan 192.168.XXX.Y

How/where do I redirect the DNS on the RB960 to the Pi-hole? Or is it better to enable the DHCP server in the Pi-hole all-together and disable on the rb960?
Would someone have the time & patience to explain/help me to set it up?
Thanks

Several options:

If you redirect the router IP will be used in the logging of the PiHole.
You better set DNS server in the /ip dhcp-server network section (from commandline it would be /ip dhcp-server network set 0 dns-server=[ip address PiHole])

thanks@erlinden
Done that step and it is working.