Assuming PC since the xbox has a default.
There's two places to enable controller. One in Playonling config and one in FFXI config. You want to enable in FFXI config and you can set the buttons from there.
____________________________On the topic of Black Mage in XIV:
They summon fireballs and fart lightning. From their eyes.
Even thinking about them makes enemies explode.
Having one in your PT is like a free ticket to defeat Absolute Virtue.
That's the reason why only one of them is allowed in PvP. Per server.
Imagine a cross-breed between Allakhazam and Sun Zu. That's a Black Mages's toenail.