How to receive json parameters correctly?

[disburden]

This is the routing method for post_authorize in the example code

async fn post_authorize(
    (r, req, state): (HttpRequest, OAuthRequest, web::Data<Addr<State>>), ) -> Result<OAuthResponse, WebError> {
) -> Result<OAuthResponse, WebError> {
    state
        .send(Authorize(req).wrap(Extras::AuthPost(r.query_string().to_owned())))
        .await?
}

The second parameter req is an OAuthRequest object, if I want to receive the json parameter uploaded by the client I have to change the type of this parameter to web::Json, then I lose the OAuthRequest object and can't do the subsequent operations.
How can I receive the json parameter correctly or can I manually create an OAuthRequest object in this method using the OAuthRequest::new() method to perform the subsequent operations.
Thank you!!!