Why can't computers get an IP from a DHCP server?

Question

Cisco Packet Tracer

Created a 3-level network, set up communication between the DHCP server and subnets. The computers ping each other, the server pings with all the computers (if you set them to a static IP), I registered iphelper-address on the router, configured DHCP pools, but the computers do not receive IP from the DHCP server. What do I still lack for the full operation of DHCP?
General scheme of the network

DHCP pools on the server

Configuring the L3 switch

Answer 1

DHCP+Relay+CISCO