Run and reinstall:

If all else fails, you might need to uninstall and then reinstall Call of Duty: Infinite Warfare.

The "steam-api64r.dll missing" error in Call of Duty: Infinite Warfare is a classic false-positive antivirus collision or a minor Steam client glitch. In 90% of cases, or running a Steam file verification will solve it instantly.

In the year 2184, long after the Call of Duty: Infinite Warfare