@shellya2025
WRT300N is a wireless router and as such it has DHCP server on it. The laptop is expected to get IP address from the wireless router.
In order to laptops get IP address from your DHCP servere either the WRT300N should be a bridge or a DHCP relay, which I believe it does not supports in PacketTracer.
One workaround would be connect the Wireless router to the switch using the wireless router lan interface. This way the laptop will get IP address from the DHCP server but, this is not totally correct.