authReturnCode.RdChecks the URL of the Shiny app to get the state and code URL parameters.
authReturnCode(session, securityCode = getOption("googleAuthR.securitycode"))
| session | A shiny session object  | 
    
|---|---|
| securityCode | A random string to check the auth comes form the same origin.  | 
    
The Google auth token in the code URL parameter.
Other shiny auth functions: createCode,
  gar_shiny_getAuthUrl,
  gar_shiny_getToken,
  gar_shiny_getUrl,
  loginOutput,
  reactiveAccessToken,
  renderLogin,
  revokeEventObserver,
  with_shiny