By creating click ads for WhatsApp/Facebook Messenger/Instagram Direct you can redirect your leads directly to the inbox of each of these three channels. Here are the first steps to do this:
Through WhatsApp
With Ads that click to WhatsApp, you can add a Send Message button to your Facebook or Instagram ads that will open a conversation thread in the WhatsApp Business App. This allows customers to connect with your business on WhatsApp after clicking the button on your ad.
Before you begin:
Create a business account by downloading the WhatsApp Business app or integrate with the WhatsApp Business API.
Connect your WhatsApp account to your Facebook page and make yourself the admin of your Page.
Through Facebook Messenger
Ads that click to Messenger work with three objectives: Messages, Traffic, and Conversions. During ad creation, you'll create both the ad and the welcome experience people see in Messenger after they click on your ad.
Before you begin: choose your objective
The Messages objective delivers ads to people more likely to respond to your business in Messenger (recommended).
The Traffic objective is designed to send people to a Messenger conversation.
The Conversions objective should be used if you're tracking events with a Facebook pixel.
Through Instagram Direct
Ads that click to Instagram Direct are shown in Instagram Feed or Stories and allow people to start a message thread with your business by clicking on your ad. Here you can interact with people directly to complete purchases, answer questions, or offer support.
Before you begin: create an Instagram Business account.
For more details on how to create each of these ads you can access the following articles from Meta: WhatsApp, Facebook Messenger and Instagram Direct,