[Need Help] Leaving puppy alone for the first time

Hey everyone. I have a 9 week old goldendoodle with extremely high energy levels and was wondering what would be the best way to slowly introduce her to the idea of being left alone. Not for long periods of time. Maximum 1 hour. I understand she's still very young.

So far, she is great when we are around and she is in her crate. When we are out of sight but in the house, she whines for a little bit, but after hearing our voices, seems to relax. The problem is when she's awake and she can't see or hear us. How am I supposed to run errands? I'm trying to reward her whenever she's chilling in the crate, and going out of sight for brief periods of time, but I'm not seeing that much progress.

Share your stories, what you did, and how things are going! Any info is useful!

Thanks!