Ultimate Weapon Quest

[Mosha]

Yes, I did the quest a few times under trials, but the quest is not completed for some reason.

must be a solo duty then

[Estariel]

https://forum.square-enix.com/ffxiv/threads/461853

Area and coordinates: The Porta Decumana (world area reached by using the passage next to The Praetorium's entrance - not the trial!)

1. Accept the quest "The Ultimate Weapon" after Patch 6.1
2. Reach the quest step "Confront Lahabrea on the Porta Decumana."
3. Speak with Lahabrea to start the solo duty

average item level 42 or above is necessary to proceed

[Lasten]

Thank You!! The entrance I needed was a small star like icon to the right of the Praetorium's entrance as you said, once I clicked on that, I talked with Lahabrea. I think earlier, I wasn't paying attention and I died and couldn't find my way back