I am assuming that your VLAN 50 will be handled locally by the IAP?
If that's the case then you need to create a local DHCP using VLAN 50 , then create an access wired profile with VLAN 50 then assign it to the port(s) .
In this example I am using port 2
ip dhcp VLAN50
server-type Local
server-vlan 50
subnet 192.168.50.0
subnet-mask 255.255.255.0
dns-server 192.168.1.103
wired-port-profile VLAN50-ACCESS-WIRED-SETTINGS
switchport-mode access
allowed-vlan all
native-vlan 50
no shutdown
access-rule-name VLAN50-ACCESS-WIRED-SETTINGS
speed auto
duplex auto
poe
type employee
auth-server InternalServer
captive-portal disable
no dot1x
enet2-port-profile VLAN50-ACCESS-WIRED-SETTINGS