dhcp response on vlan

I have configured a vlan with id 20 on switch0.20

address 10.150.1.1/24
mtu 1500
switch-port {
interface eth2 {
}
interface eth3 {
}
interface eth4 {
}
}
vif 20 {
address 10.150.20.1/24
firewall {
in {
name public_vlan
}
}
mtu 1500
}

 and a dhcp server with

authoritative disable
subnet 10.150.20.0/24 {
default-router 10.150.20.1
dns-server 75.75.75.75
dns-server 75.75.76.6
lease 7200
start 10.150.20.10 {
stop 10.150.20.250
}
unifi-controller 54.91.106.205
}

what else do i need to do to get dhcp on my vlan?

Please help.