In the Showtime chapter, you need to activate the Main Stage to move forward. This guide will show you how you can activate the Main Stage and move forward in the Showtime chapter.
After starting the chapter, simply follow Freddy up to the Main Stage. After his dialogue, head south towards the Prizes sign. Climb up the escalator and turn right. Be careful, security bots are roaming in this area as well.
Climb up the escalator to your right and you should come across some arcade machines. Hug the wall to your right to avoid the security bots. Keep going north until you reach the Prizes area.
Parallel to it is the Sound Booth filled with computers. Use your Showtime Disk on top of the desk that has 2 active monitors. Backtrack your way to the Main Stage. You will find a Save Spot on the second floor.
Interact with the Save Spot to save your progress. Sprint towards the stage to avoid Monty and Chica. Afterward, press the button on the main stage and follow Freddy to the Recharge Station.
And there you have it, just enter the Recharge Station and your mission is complete.