app-ads.txt
Implementing app-ads.txt in your app following steps:
Step 1.Overview
Step 2.Set up an app-ads.txt file for your app
Step 3.Publish your app-ads.txt file on your developer website
Step 4.Add your developer website in your app store listing
Overview
Authorized Sellers for Apps, or app-ads.txt, is an IAB Tech Lab initiative that helps ensure your app ad inventory is only sold through channels you’ve identified as authorized. Creating an app-ads.txt file gives you more control over who’s allowed to sell ads on your app and helps prevent counterfeit inventory from being presented to advertisers.
The app-ads.txt files are publicly available and crawlable by exchanges, supply-side platforms (SSP), and other buyers and third-party vendors.
Authorized Sellers for Apps (app-ads.txt) is an extension to the Authorized Digital Sellers (ads.txt) standard, originally designed for protecting web ad inventory. It extends compatibility to support ads shown in mobile apps.
To prevent a significant loss in ad revenue, you'll need to implement an app-ads.txt file.
Reference: About app-ads.txt
This is a app-ads.txt file example:

Set up an app-ads.txt file for your app
Below is an example of the app-ads.txt file. Before the app goes live, please go to the application list in the trek backend to obtain your ads.txt or app-ads.txt file. that is exclusive to your app.

Publish your app-ads.txt file on your developer website
The hostname is determined from your app's developer website.Here is a example.
Add your developer website in your app store listing
To add your developer website in your app store listing:
For Google Play: Add the website URL in the contact information of your app listing:
Sign in to your Play Console.
Select an app.
On the left menu, click Store presence > Store listing.
Scroll to Contact Details.
Add your developer website URL.
For Apple App Store: Add your developer website in the marketing URL field of your store listing.
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