title: Why 1.0 OAuth flow Twitter of a third app doesn't recognize that the user is already logged in?
body: <p>The authorization with OAuth1.0 sends me to a new authorization page, also from Twitter (<a href="https://twitter.com/i/flow/login?input_flow_data=%7B%22requested_variant%22%253A%22..." rel="nofollow noreferrer">https://twitter.com/i/flow/login?input_flow_data=%7B%22requested_variant%22%253A%22...</a>). Furthermore, when I am already logged in on Twitter, the second authorization is never successful. The process of the two authorizations is successful only when I do it for the first time in an incognito browser page.</p>
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-html lang-html prettyprint-override"><code>app.get("/",(req,res)=&gt;{
      if(req.cookies.logged == undefined){     //User not logged
          res.render("index",{logged:false});
      }
      
      else if(req.cookies.user_name == undefined){     //OAuth phase 3 
          //3 step : ottenimento token
          const req_data = qs.parse(req);
          var url = "https://api.twitter.com/oauth/access_token?oauth_token="+req.query.oauth_token+"&amp;oauth_verifier="+req.query.oauth_verifier;
          request.post({url:url},(e,r,body)=&gt;{
              const body_data = qs.parse(body);
  
              utils.setCookie("oauth_token",body_data.oauth_token,res);
              utils.setCookie("oauth_token_secret",body_data.oauth_token_secret,res);
              utils.setCookie("user_id",body_data.user_id,res);
              utils.setCookie("user_name",body_data.screen_name,res);
      
              res.render("index",{logged:true,username:body_data.screen_name});
          });
      }
  
      else{                                   //User alredy logged
          res.render("index",{logged:true,username:req.cookies.user_name});
      }
      
  });
  
  
  app.get("/login",(req,res)=&gt;{
      //1 step: Get access_token
      var url = "https://api.twitter.com/oauth/request_token";
      request.post({url:url,oauth:twitterOAuth},(e,r,body)=&gt;{
          const req_data = qs.parse(body);
          
          //2 step: authorization resource owner
          url = "https://api.twitter.com/oauth/authorize?oauth_token="+req_data.oauth_token;
          request.get({uri:url},(e,r,body)=&gt;{
              utils.setCookie("logged",true,res);
              res.end(body);
          });
      });
  });</code></pre>
  </div>
  </div>
  </p>