Remove This Application Was Created By A Google Apps Script User ((link)) Free
If you have a (even the free legacy edition), you can publish the script internally without verification.
In your Apps Script editor, go to Project Settings and click "Change Project." Enter your Project Number. Configure your OAuth Consent Screen in the GCP Console. If you have a (even the free legacy
The most common "legitimate" workaround is to embed your Apps Script Web App into a Google Site. the free user).
"This application was created by a Google Apps Script user." If you have a (even the free legacy
// Encode the message var encodedMessage = Utilities.base64EncodeWebSafe(raw);
This message appears because your script hasn’t been verified by Google. It’s Google’s way of warning users that the app comes from an unverified developer (you, the free user).

