All characters from oauth?

Not really, at least for what you are trying to do. You can find all about character and user profile in the official documentation.

To get a list of a user’s character you must consume the first endpoint described in the link I provided (Account Profile Summary).

For the PHP part you can follow this thread.

Just a few hints:

  • There is no profile API for WoW Classic
  • Do not mistake an access_token with an authorization_code
  • Make sure you are using the authorization code flow to get access to a user profile.

Please take your time to carefully read the documentation and if you still have questions we are here to help.