IOS ASWebAuthenticationSession for OAuth

Can you share the full URL of the page displaying the error, as well as the text of the error itself? Thanks in advance! 

    static let CLIENT_ID = "......"
    static let CLIENT_SECRET = "...."
    static let REDIRECT_URL = "myapp://Auth"
    static let OAUTH_URL = "https://www.dropbox.com/1/oauth2/authorize"
    
    override func OAuthURL() -> String {
      return String(format:"%@?redirect_uri=%@&response_type=code&client_id=%@&force_reapprove=true",
                    DropboxOAuthInfo.OAUTH_URL,
                    HTTP.urlEncode(DropboxOAuthInfo.REDIRECT_URL),
                    DropboxOAuthInfo.CLIENT_ID)
    }

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Thanks! Based on the code you shared, I see that you're using the "code" flow (i.e., 'response_type=code'). For the code flow, only "https://" is allowed in the redirect URI (unless on localhost), so "myapp://" wouldn't be allowed.

Instead, for client-side applications like this, you should use the "token" flow, i.e., 'response_type=token'. That does allow custom URL schemes in redirect URIs, such as "myapp://". 

For more information on how to use the token flow, please refer to the /oauth2/authorize documentation.