Follow the prerequisite links here: https://ffxiv.gamerescape.com/wiki/I...We_Can_Kill_It for the Ifrit one. The prerequisite may already be on your quest list https://ffxiv.gamerescape.com/wiki/A_Recurring_Problem,, in which case, go find Urianger in the Waking Sands.

The other two primal fights will follow once the quest [and Ifrit (Hard)] has been completed.