If you're using an advertising service such as Google Adsense, they might ask you to setup an 'ads.txt' file on your site.
Here we will show how to create an ads.txt file using either WordPress or Blogger/Blogspot.
WordPress
The easiest way to create the ads.txt file on your WordPress site is to use the free Ads.txt Manager plugin.
Blogger/Blogspot
You can access the ads.txt settings in Blogger/Blogspot by going to Settings > Search preferences in your blog's dashboard. This allows you to copy and paste the required information into your blog's ads.txt file.