How to open a game hall task for gta5?

You need to complete the pre-task of the casino first. Let me tell you the order from the beginning.

Buy a room in the casino first, then go to the room to trigger the plot, and then give you a series of tasks in the casino. This is necessary. After that, the casino will give you a car (let you pick it up somewhere), and then Lester will send you a text message asking you to go somewhere. After the story is over, he will tell you to buy a game hall, and then you can trigger the story to take over the task under the game hall.