Assuming you would like to know how to become an admin user for Google App Engine, there are a few ways you can go about doing this.
The first way is to simply ask your Google App Engine account owner to make you an admin. They can do this by going to the Permissions tab under your project settings and adding you as a Project Owner or App Engine Admin.
The second way is to become an owner of the Google Cloud Platform project that your App Engine app is residing in. You can do that by going to the IAM & admin section of your Cloud Console, selecting your project, and adding yourself as a Project Owner. Once you are an owner of the project, you will automatically be an admin for the App Engine app as well.
The last way is to create a new App Engine app with you as the sole owner. When you create a new App Engine app, you are automatically made an admin for that app.
You can find more detailed instructions on how to become an admin user for Google App Engine here:
https://developers.google.com/appengine/docs/admin-api/overview