How do I connect my pre-existing Xbox account to the app?

Hi Baner27! I hope you are well, delighted to be able to offer you my help!

Press the Xbox Guide button on your controller (large X button in the center of your controller). Select Download Profile. Enter the Windows Live ID associated with your Xbox Live gamertag. If you don't know your Windows Live ID or password. Now, enter your Windows Live ID password. Select the storage device for your profile (e.g. hard drive)

Your profile will begin downloading. After downloading your profile, you can choose whether to require a Windows Live ID password to sign in to your profile.

I hope this information is useful for you, otherwise I will be attentive to continue helping you.

Best regards,
Daniel.

That’s outrageous. How do I create a separate account for a pre existing account ie my daughters account . Do I have to start from scratch for her?

Also, I've been sent links by the EA folks on how to link a gamertag to an Origin account, but the problem still exists that it wants me to pick a new gamer id (which I shouldn't have to do because I already have one), and when I enter my pre-existing one,
it says it's already taken! The EA people were going to help me merge the pre-existing account (that's tied to a decade old email that's apparently no longer working) to this weird 'account' thats asking me to pick a new gamer id, but only if I can gain access
to that decade old account that's apparently no longer working. What's going on & how do I fix it?

There is no way to merge accounts. You would need to join live with your offline account and sign into it on the One in order to use it.

I do not have an xbox live account just a xbox game bar account and Microsoft account because I do not own a console just a PC to do gaming on. It didn't direct me to do anything the xbox accessories app just has configure greyed out. My xbox accessories
app is up to date as well this is just an issue of the app not registering my existence on PC.