I really think you don’t understand.
When you use the authorization code WF, the account the user use to log in, can be any account. It’s not related to the partner account. The partner account give an API key and secret and a redirect url. So the user is sent to an authorization page to login and authorize the “partner/app” to log in using your account.AFter, they are sent back to the app using the redirect url.
For example, my sandbox account is on email@example.com
I can call the root endpoint with this access token and get all the ID. But There’s no ID linked to my partner account because I don’t use this account to log in to your API.
Really, when I say authorization code WF (with the link to the documentation) you don’t seem to know what I’m talking about. You always refer to the client credentials where, for example, the user firstname.lastname@example.org will need to provide me his API key and Secret to get an access token. This is not needed in authorization code WF. User just login, say yes I give authorization to the app and go back to the redirect url with a CODE. This code is exachanged to get an Access token for this account.