Port Forwarding Not Working

Hi all

I am very new to Fortigate. Just set up a FG 60F that needed port forwarding from a cloud service to an internal printer on port 9102.

What I have done so far:

Set up VIP with external IP of WAN interface and internal IP of printer:

Created firewall policy with the source being the public IP of the cloud service, destination the VIP

Debug logs give these messages:

id=65308 trace_id=9 func=init_ip_session_common line=5995 msg="allocate a new session-0009a61c"
id=65308 trace_id=9 func=get_new_addr line=1205 msg="find DNAT: IP-<printerIP>, port-9102"
id=65308 trace_id=9 func=fw_pre_route_handler line=180 msg="VIP-<printerIP>:9102, outdev-wan1"
id=65308 trace_id=9 func=__ip_session_run_tuple line=3413 msg="DNAT <WAN_INT_IP>:9102-><PrinterIP>:9102"
id=65308 trace_id=9 func=vf_ip_route_input_common line=2611 msg="find a route: flag=00000000 gw-<printerIP> via internal"
id=65308 trace_id=9 func=__iprope_tree_check line=539 msg="gnum-100004, use addr/intf hash, len=3"
id=65308 trace_id=9 func=fw_forward_handler line=827 msg="Denied by forward policy check (policy 0)"
id=65308 trace_id=10 func=print_pkt_detail line=5811 msg="vd-root:0 received a packet(proto=6, <cloud server_public_IP>:57804-><WAN_INT_IP>:9102) tun_id=0.0.0.0 from wan1. flag [

Apologies if I have missed something very basic!