If you're referring to Messenger on Facebook, you can see your phone contacts on Messenger by syncing your phone contacts with your Facebook account. To do this, go to your Messenger settings, select "People," and turn on the "Sync Contacts" option. Once synced, you should be able to see your phone contacts who are also on Facebook and Messenger. If they are not on Facebook or Messenger, you won't be able to see them in the app.