Start up code?!?!?

I am assuming they are the same app. I thought they were different apps as well, but when I try to find the smart glass app, it takes me to the xbox app in the play store

Hello Coffee,

We understand that you're experiencing an issue involving a startup code mentioned as part of the process for the
Xbox Smart Glass.

We would like to clarify that this is the correct app you're referencing, or if you are inquiring about the
Xbox App?

Is it explained by the app what the code is used for?

Clarify this for us and let us know the results.

Best wishes!

Hey Coffee,

After missing that window, there is no going back. You are going to have to link your xbox to the Xbox app manually now.

you must first enable game streaming from your Xbox One. To do this, press the
Xbox button to open the guide, select Settings >
Preferences > Xbox app connectivity. Do these two things:

1. Under This Xbox, select Allow game streaming to other devices.
   
2. Under Other devices, select Allow connections from any device or
   Only from profiles signed in on this Xbox.

Theses next steps would be on the Xbox app on your PC :

1. On your PC, launch the Xbox app.
2. Select Connection from the panel on the left side.
3. The Xbox app will scan your home network for available Xbox One consoles. Select the name of the console you want to connect to.
   

Hope this helps!

That code is usually related to a system update. Have you tried an offline system update? See the instructions here:

https://support.xbox.com/en-US/xbox-one/console/system-updates-solution

If that does not work, then you can try an offline factory reset, see here:

https://support.xbox.com/en-US/xbox-one/console/reset-factory-defaults-using-usb-flash-drive

Good Luck!

try to power cycle your console. Please hold down the power button on the front of the console for approximately 15 seconds until the power light shuts off. Wait about 60 seconds, then power it back on. Be sure you see the green "XBOX ONE" animation loading
screen when you power it back up.

if this don't help

Reset Console

How to reset your console to factory defaults on Xbox One https://support.xbox.com/en-US/xbox-one/console/reset-console-to-factory-defaults

How to reset your Xbox One console to factory defaults using a USB flash drive https://support.xbox.com/en-US/xbox-one/console/reset-factory-defaults-using-usb-flash-drive

But remember choosing one of this two erase all data you need to install all again