There is a lot of curiosity about the Perfect Shot quest in Genshin Impact at the moment, but this is not something that currently be completed. The quest is tied to the Five Flushes of Fortune event, and is not available in the game just yet.
When the Five Flushes of Fortune event ends, you will be able to start the Perfect Shot quest, but it will remain closed until then.
The Five Flushes of Fortune event should wrap up around February 13. When it is complete, go and speak with Ji Tong in Liyue. Ji Tong is the NPC who looks after the Five Flushes of Fortune event, and is the person who original gives you the Kurious Kamera that you use during the event.
Not a huge amount is known about the Perfect Shot quest right now, but we will be updating this guide into a full detailed walkthrough as soon as it is available in the game. It is currently thought that the reward for the Perfect Shot quest will be a permanent version of the Kurious Kamera that you can use in the game. This Special Kamera will take more interesting photos than the screenshot mode in the game, so looks like a fun option for people who like to take nice screenshots in the game.