Hello @The-Burro_1. 

You can login to the router web management page by wiring a computer to it with an Ethernet cable, then you should be able to find the password as follows:

How to find or change the wireless password on the TP-Link products

  @Kevin_Z, to resurrect this post, I no longer have the sticker on the bottom of the router, yet I do have the box it came in from Hom Depot.

Is there a way to log in and change the password and get this paperweight finally online?

Burro

@The-Burro_1. 

I understand that the device sticker is no longer available and that's why I asked you to connect a computer to the AX4400 with an Ethernet cable, then you can try to access the router web management page by typing tplinkwifi.net in the address bar of the browser, it will ask for a login password. 

If you don't know this login password, you will need to reset the router to factory defaults, then reconfigure it from scratch, and below are the detailed instructions to reset the router:

How to reset TP-Link router to factory defaults

After the reset, you can reconfigure the router as per the requirements of your ISP, and you can follow this guide also:

How do I install TP-Link Archer router to work with a Cable Modem?

How do I install TP-Link Archer router to work with a DSL Modem?

I hope this helps.