Mac users can run unnotarized apps, but in macOS Sequoia there have been some changes that make it slightly more complex. Instead of control-clicking, you'd need to go to System Settings and allow the app to run.
From what I know, you need to enroll in the developer program to notarize and distribute your apps (not necessarily via the App Store), but correct me if I'm wrong.
Topic:
Code Signing
SubTopic:
Certificates, Identifiers & Profiles