Use a lock screen PIN, password, or fingerprint
Turn off message previews on the lock screen
Enable notification privacy settings to hide content
Use the Messages app archive feature
Move chats to a secure folder or private space if your phone supports it
Use a third-party app with app lock or hidden chat features
Disable notifications for the messaging app
Use a separate messaging app with disappearing messages
Clear message notifications after reading
Delete sensitive messages after saving anything important elsewhere