This article explains how to invite someone you have in your address book or on Facebook to download Messenger.
Steps
Step 1. Open the Messenger app
It represents a white lightning bolt on a blue background.
If you are not logged in, type in your phone number, tap "Continue" and enter your password
Step 2. Tap People at the bottom right
If Messenger opens a specific conversation, first tap the arrow in the top left
Step 3. Tap the All Contacts option
It is located under the "Search" bar at the top of the screen.
Step 4. Tap Invite People at the top of the screen
You can also scroll down and tap the "Invite" button, which is located to the right of each contact who doesn't use Messenger
Step 5. Tap Invite next to each contact you want to invite
In this way you will receive a link to download Messenger on your device (Google Play for Android and App Store for iPhone).