如何在用户注册后根据单选按钮wordpress重定向

我试图在用户注册后重定向页面。我在用户注册中创建了两个单选按钮paynow和paylater。我想在用户点击paynow时重定向。用户应该注册并重定向到自定义url。如果用户选择paylater，用户应该注册和发送自定义url给用户以备将来付款。这是我使用的代码

    $myemail=$_POST['email'];
        $first_name="firstname";
         $last_name="lastname";

    echo "<script>window.location.href='https://www.payumoney.com/?firstname=$first_name&last_name=$last_name'&email=$myemail'</script>";

    $to="test@gmail.com";   
    $message = "
    Please payus for registering account https://www.payumoney.com/?firstname=$first_name&last_name=$last_name'&email=$email'
    ";
    // To send HTML mail, the Content-type header must be set
    $headers  = 'MIME-Version: 1.0' . "'r'n";
    $headers .= 'Content-type: text/html; charset=iso-8859-1' . "'r'n";
    // Additional headers
    $headers .= 'To: madu<test@gmail.com>' . "'r'n";
    $headers .= 'From: madu<test@gmail.com>' . "'r'n";

    // Mail it
    mail($to, $subject, $message, $headers);
    }
    }
    add_filter( 'registration_redirect', 'wpse_19692_registration_redirect' );

Radio buttons
add_action( 'register_form', 'myplugin_register_form' );
function myplugin_register_form() {
    $first_name = ( ! empty( $_POST['first_name'] ) ) ? trim( $_POST['first_name'] ) : '';
        ?>
        <p>
            <input type="radio" name="paystatus" id="paystatus" value="paynow">Pay Now<br>
             <input type="radio" name="paystatus"  id="paystatus" value="paylater">Pay Later
        </p>
        <?php
    }
    //2. Add validation. In this case, we make sure first_name is required.
    add_filter( 'registration_errors', 'myplugin_registration_errors', 10, 3 );
    function myplugin_registration_errors( $errors, $sanitized_user_login, $user_email ) {
        if ( empty( $_POST['first_name'] ) || ! empty( $_POST['first_name'] ) && trim( $_POST['first_name'] ) == '' ) {
            $errors->add( 'first_name_error', __( '<strong>ERROR</strong>: You must include a first name.', 'mydomain' ) );
        }
        return $errors;
    }
    //3. Finally, save our extra registration user meta.
    add_action( 'user_register', 'myplugin_user_register' );
    function myplugin_user_register( $user_id ) {
        if ( ! empty( $_POST['paystatus'] ) ) {
           $checkme= update_user_meta( $user_id, 'paystatus', trim( $_POST['paystatus'] ) );
        }

    }
?>