Your device will vibrate when lifted to alert you of missed calls and messages.
Here's how Smart Alert works on Samsung Galaxy J3 Pro:
Step 1:
Go to 'Settings' and select 'Advanced features'.

Select 'Advanced features'.
Step 2: Select 'Smart Alert'.

Select 'Smart Alert'.
Step 3: Turn on the feature.

Activate the feature.
Your setup process is now complete. Wishing you all success.