why does the same request keep hitting my server even though I didn't call the endpoint

I have a question to something I tried to resolve but it seems to keep happening. I have a simple server endpoint /example and I call that endpoint from a curl 123.45.678.901/example and the server runs a function and returns something to me and then I res.end(), but I noticed that after a while the endpoint is hit again even though I didn't call it and I can see on the terminal where the server is open one of my console.logs appears. This is the code

const express = require ("express");
const app = express();
const port = 80;

//middleware function
const authenticateUser = (req,res,next) => {
  console.log("header w/ access_token sent in:", req.header("token"))
  request.get({
   url: [url here were I authenticate the token they sent me]
  }, function optionalCallback(err, httpResponse, body){
       if (err) { 
         res.send("Authentication failed, please check your access_token");
         res.end();
       }
      console.log("Authentication has been cleared");
    next()

  })
}

//here I tell express to use my middleware always
app.use(authenticateUser);

app.get("/example", (req,res) =>{
             console.log("in /example endpoint");
             (some function being called here that returns something to the client)
             res.end();

})

app.listen(port, () => console.log(`App is listening on port ${port}`));

this is what I see when the ghost call is made to the server, I know I didn't call the endpoint because if I had the undefined I see there would show a token I pass in through Headers in the cURL:

enter image description here