How can I use iPhone 16 Pro Max for reverse charging?

Hello,

Yes, it should have reverse wired changing.

Connect both devices with a cable that has USB-C on both ends. Then the device with the lower charge should receive charging from the one with the higher charge.

Good luck.

Be aware however that using reverse charge will put additional strain on your 16 Pro's battery thus shortening its life. How much depends on how often you use it that way.