How to add suggetionbox in web when cursor is on button
Solution 1:
Try below code hope its help to you. Used Tooltip Widget
Refer Tooltip here
Test below code here
Tooltip(
message: "Managers",
child: ElevatedButton(
onPressed: () {},
child: Text('OK'),
),
),
Result Screen-> 
Solution 2:
You need to wrap widget with Tooltip see example.
flutter tooltip example