If you are not using the automatic redirect for Ads.txt you will have to check for new updates periodically.
- Visit your Publisher account in Advally Reporting
- Click on "Sites" to get the list of sites, then click "Ads.txt"
- Click on the "Verify Ads.txt" button
- The verify results will indicate of there are outdated lines
If there are outdated lines, from the Ads.txt page click on "Download Latest Ads.txt", and upload this version to your site under "/ads.txt".