You can use the Adjust SDK to record activity from apps that came preinstalled on a user’s device. This allows you to collect data from users who didn’t download your app as part of a campaign.
Default link token
Configuring a default link token lets you attribute all preinstalls to a predefined Adjust link. Adjust records all activity against this token until the attribution source changes.
- 
Create a new campaign link in Campaign Lab.
https://app.adjust.com/{token} - 
Copy this token and assign it to the
defaultTrackerkey of your config table. 
local adjust = require "plugin.adjust"
adjust.initSdk({    appToken = "YourAppToken",    environment = "SANDBOX",    logLevel = "VERBOSE",    defaultTracker = "abc123"})- 
Build and run your app. If you have logging enabled, you should see a message in your log
Default tracker: 'abc123'.