The objective of this quest is to prepare and deliver a Cactus Smoothie to a group of weary Gerudo soldiers located in the southern part of the Gerudo Desert.
How to Complete the Southern Gerudo Desert Rift Main Quest
Zelda needs to travel south from Gerudo Town to find a small group of exhausted Gerudo soldiers. Upon speaking with them, Dohna will appear and suggest that Zelda should obtain a Cactus Smoothie from the Smoothie Shop situated near the Oasis. Dohna will provide Zelda with two Chilly Cacti, which are required ingredients for the smoothie. Zelda must then warp or travel to the Oasis and visit the Smoothie Shop. Using the two Chilly Cacti, she can create a Cactus Smoothie (the recipe typically involves Chilly Cactus and Floral Nectar).
Once the smoothie is prepared, Zelda must return to the group of soldiers located south of Gerudo Town and give them the Cactus Smoothie. Upon receiving and consuming the smoothie, the soldiers will be revitalized, and the quest will be successfully completed.