🔒Make it private
When the app should not be open to anyone with the link, switch to a Private app, choose a login method, and (usually) restrict which Notion rows each user can see.
Steps
Open Users in the builder rail.
Set the app to Private (see Private apps).
Create or link a Users database and add at least one test user.
Choose a login method that is available today (email OTP is always available; Email & password, Google, Auth0, and Okta are entitlement-gated).
Configure Data Restriction / personalization so users only see their rows.
Publish again, then open the app while signed out — you should hit login.
Auth overview
See the full matrix: Auth and access
Related
What’s next after your first private app
Add a Form (Add Item) or Form (Update One Item)
Try Board layouts
Explore Automation if you need approvals or routing