How can I activate notifications and lock screen notifications on a Xiaomi mobile phone?

Navigate to the Settings page.
Select Lock screen and enable Wake Lock screen for notifications.
Go back to the Settings page and choose Notifications.
Select Lock screen notifications, and activate the toggle for the preferred Apps.
Head back to the Notifications page and choose Floating notifications. Activate the toggle for the preferred Apps.
Revisit the Notifications page and select Notification badges. Activate the toggle for the preferred Apps.
Go back to the Settings page and select Battery & performance.
Deactivate Battery saver and Ultra battery saver. (When these two toggles are active, the system will block related notifications.)
Return to the Settings page and choose Permissions under App Settings.
Select Autostart and activate the toggle for the preferred Apps.
Go back to the Permissions page and choose App permissions.
Select the desired App and enable Show on lock screen.
Start in background, and Display pop-up window.