"wAP ac" ap setup issue

Hi guys,

I am a newbie of mikrotik, and suddenly buy a 2011u router, RB951 switch, and a wAP ac for my office use, but here i confront an issue, i can’t obtain dhcp on my wAP ac device, in fact i wanna use
2011u as the dhcp server to assigned ip address to all of the devices. but in vain, and then i try to setup wAP as dhcp server but still not thing happen. is there any one give me a help to fix this glitch. Thank you!!!

here are my structures and evidence.
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