If someone owned it prior or it was a returned product, someone might have changed them already. If this is so, try factory resetting it (push and hold reset for 7-10 seconds while powered up)
here's your support site with manuals, firmware, and install guides. It should have the option to login to the router manually and not using the app if you'd like to try that.
Your subject says AC2300, but the "footer" says AC2400. Which is it?
AC2300 is not a reliable guide to model number. Many devices come with an AC tag, but it is essentially a label that Netgear, and other brands, attach to hardware to describe wifi speeds.
