Warning: Starting on or after April 8, 2019, the Google Cloud Platform Console won’t be able to access the default GCP projects created for new Apps Script projects. Older, existing scripts may have default GCP projects that are still accessible, however. If you have a new script and require access to its GCP project from the Google Cloud Platform Console, you must use a standard GCP project., see the official webpage.
You must switch your script project to use a standard GCP project
Warning: If your script was using its default GCP project and you switch your script to use a standard GCP project, the script’s default GCP project is deleted, which has the following irrevocable effects:
You lose any data tied to advanced services that you enabled for that script (because advanced services rely on the GCP project).
All users who have previously authorized the script must re-authorize. In most cases, all users who have previously authorized apps associated with the new GCP project must also re-authorize.
If your script is associated with an app listing on the Google Workspace Marketplace, your app listing, users, and reviews don’t carry over to the Standard GCP project. You need to create a new app listing within the Standard GCP project and your users need to reinstall your app.