<?php
        $sql = $mysqli->query("SELECT * FROM accounts WHERE username ='$username'");
        $row = mysqli_fetch_array($sql,MYSQLI_ASSOC);
        $hash = $row['password'];

        if (password_verify($hash, $password)){
            echo "password valid";

        }else{
             echo "password invalid";
        }

?>

<?php

        $encrypted = password_hash($password, PASSWORD_DEFAULT);
?>