In the end, I managed to conquer the area with the help of Rifai and some of my members who were already there. Tiara, Kahfi, Joko, Elvina, Helena, Bagas, and Pretty completed the quest before the time limit ran out. Until now, I had no clue what the food was and only knew that they had finished with difficulty.
Bagas sent me a video message in the Chat Menu. The video shows the faces of Tiara, Helena, Kahfi, Joko, and Elvina who look happy smiles while carrying the NPC who is conscious and has no poison in his body. I'm sure, they are struggling to find the purpose of the quest, it can be seen from their faces that are smiling happily as if they have won the battle alone. The video lasted only a few seconds, and under the video were the words, "Thank you, Sensei! We are proud to be your students. Once again, thank you!" from Bagas.
At that time I just smiled and said to myself, "Tch. It is the leader's job to make the members comfortable."