Configure hEX and wAP ac

Hi!
I need some help on configure hEX (RB750Gr3) and wAP ac (RBwAPG-5HacT2HnD).
hEX is used as router connected to Internet on port 1.
wAP ac is connected to hEX port 2.
wAP ac should be configured with WiFi 2.4 GHz “bgn” and 5 GHz “ac”.