How can I dial the phone from Flutter?

This method will open the dialer :

_launchCaller() async {
    const url = "tel:1234567";   
    if (await canLaunch(url)) {
       await launch(url);
    } else {
      throw 'Could not launch $url';
    }   
}

EDIT:

In case anybody facing errors:

Add url_launcher: in the pubspec.yaml & run flutter get

Also import 'package:url_launcher/url_launcher.dart';