Add modules to your app-level build.gradle file
Replace [latest-version] with the numerical part of:

Android Auto Support
implementation "chat.sdk:mod-auto:[latest-version]"
Allow users to have multiple profile pictures
implementation "chat.sdk:mod-profile-pictures:[latest-version]"
Enable drawer mode
implementation "chat.sdk:mod-ui-extras:[latest-version]"
Allow users to search and invite using their contact book
implementation "chat.sdk:pro-contact-book:[latest-version]"
Enable audio messages
implementation "chat.sdk:pro-message-audio:[latest-version]"
Enable file attachment messages
implementation "chat.sdk:pro-message-file:[latest-version]"
Enable sticker messages
implementation "chat.sdk:pro-message-sticker:[latest-version]"
Enable video messages
Enable end-to-end encryption
Enable blocking for Firebase
Enable last online indicator for Firebase
Enable display of nearby users
Enable read receipts for Firebase
Enable typing indicator for Firebase
Enable read receipts for FireStream
Enable typing indicator for FireStream
Enable typing indicator for FireStream
Enable read receipts for XMPP
Modules are available to users who sponsor the project. For more information visit our Module Licensing Page for more details.
pro-firebase-read-receipts
pro-firebase-typing-indicator
pro-firestream-read-receipts
pro-firestream-typing-indicator
pro-firebase-nearby-users
Note: The each tier includes all lower tiers. So Diamond tier includes Silver and Bronze tiers etc...