solution:
Change or Modify in Column name when you can assign the values (usernamec, passwordc) this one.

let info ={"username": req.body.USERC,"password": req.body.PASSC} 

whenever you can insert the data Column name will be same as the Database table Col name.means Both are same not different

Firstly, please check your request params(USERC, PASSW)DataType and
Values.
then Second thing, console the error

con.query('INSERT INTO users SET ?',info, function(err, result){
if(err)  
 console.log(err);
 console.log(result);
});

});

InCase Query Error you can get and resolved it.

Another Simple Way runs the Query in PHPMyadmin Manually.
Example:

INSERT INTO users SET `username`= 1 and `password` =`HELLO MYSQL`;

I am trying to write a simple login page using node.js, HTML, and MySQL. A problem I ran into was adding entries to my sql db.

con.connect(function(err) {
  if (err) throw err;

});
app.post('/create', function(req, res) {
 var info ={
 "usernamec":req.body.USERC,
 "passwordc": req.body.PASSC
 }

con.query('INSERT INTO users SET ?',info, function(err, result){
  console.log(result);
  });
 });

Everything seems to be working except for the actual query, which returns undefined. What could I be doing wrong? The picture below is my database.