There's no WLAN driver for that board for the simple reason it has no built-in WiFi adapter, very few desktop motherboards are WiFi equipped since WiFi is primarily for portable devices, not fixed-location desktop PCs.
If you read the board specs, there's no mention of WiFi or WLAN adapter:
https://www.gigabyte.com/Motherboard/GA-990FXA-UD3-R5-rev-10#sp
You have to install your own WiFi adapter (PCI-e card or USB stick) on that board, but using ethernet is always preferable where possible.
I've never understood why anyone would prefer WiFi over ethernet on a desktop PC, just laziness I guess, but there's always a solution to avoid having to use WiFi on a desktop PC - - - just needs thought and planning & maybe a bit of work.
Even...