iOS

For iOS you need to set a usage description in your info.plist file. (Privacy Setting) Open xCode search for your info.plist file and press the tiny "+". Add the following entry:

Privacy - Contacts Usage Description

Give it a value like:

"We need access to your contacts in order to do something."

Android Notes

For Android you have to add the permissions in your AndroidManifest.xml. Add the following permissions before the closing of the "manifest" tag.

<uses-permission android:name="android.permission.READ_CONTACTS" />

Next import the capContacts class to your MainActivity

// Initializes the Bridge
this.init(savedInstanceState, new ArrayList<Class<? extends Plugin>>() {{
  // Additional plugins you've installed go here
  // Ex: add(TotallyAwesomePlugin.class);
  add(Contacts.class);
}});

Make sure to import it properly as well.

import com.xofttion.capacitor.plugins.Contacts;

NOTE: On Android you have to ask for permission first, before you can fetch the contacts. Use the getPermissions() method before you try to fetch contacts using getContacts().