Recently I got a mini-computer, using i340-T4 to expand the Gigabit interface, intend to use 9260ac as AP, there is no way to drive 9260ac, ask for help
How far have you gotten? Can you see the card at all in the boot log?
As a heads up, most Intel cards often don't work as APs, but only as clients, and then only one band at a time (in general, not an OpenWrt-driven limitation).