Creating Fortilink 802.3ad send DHCP for switches but not access points connect down stream ports

I have created Fortlink with dedicate to Fortiswitch checked. I setup internal DHCP and connected POE switch with Access Point. I am getting DHCP management address to switches but not getting DHCP from downstream port where access point is plugged in. There is no way to tag Fortilink interface in any downstream switch port unless I create interface type vlan. 

My question is, is there any way to use Fortilink as management vlan to provide DHCP for switches and DHCP also for  access points only using Fortilink rather creating a separate interface type vlan under Fortilink and add downstream switchports to it. I would like to know if this is possible.