authorizeFromControllerV2 error when authorizing

I am trying to switch from a long-life token to a short one.
I am using SwiftyDropbox SDK version 7.0.1

I am following the instructions on the readme tutorial on GitHub: 

https://github.com/dropbox/SwiftyDropbox/tree/7.0.1 

In the "Begin authorization flow" section,
I change the function to:

authorizeFromControllerV2

Now when I press on "Allow" in dropbox permission pop I am getting an error:

"Error Authorizining App. An error occurred authorizing your app. Please try again"

I saw this post and added SceneDelegate file to my project and added this code inside:

    func scene(_ scene: UIScene, openURLContexts URLContexts: Set<UIOpenURLContext>) {
        if let url = URLContexts.first?.url {
            
            let oauthCompletion: DropboxOAuthCompletion = {
              if let authResult = $0 {
                  switch authResult {
                  case .success:
                      print("Success! User is logged into DropboxClientsManager.")
                  case .cancel:
                      print("Authorization flow was manually canceled by user!")
                  case .error(_, let description):
                      print("Error: \(String(describing: description))")
                  }
              }
            }
            DropboxClientsManager.handleRedirectURL(url, completion: oauthCompletion)
            
        }
    }

It didn't help. 
When I click on cancel instead of Allow I am getting back to the AppDelegate file.