The elevated button widget has a shape property which you can use as shown in the below snippet.
```dart
ElevatedButton(
style: ButtonStyle(
shape: MaterialStateProperty.all<RoundedRectangleBorder>(
RoundedRectangleBorder(
borderRadius: BorderRadius.circular(20.0),
side: BorderSide(
color: Colors.teal,
width: 2.0,
),
),
),
),
child: Text('Submit'),
onPressed: () {},
),
```
You can use the `ElevatedButton` Widget. The elevated button widget has a `shape` property which you can use as shown in the below snippet.
ElevatedButton(
style: ButtonStyle(
shape: MaterialStateProperty.all<RoundedRectangleBorder>(
RoundedRectangleBorder(
borderRadius: BorderRadius.circular(18.0),
side: BorderSide(
color: Colors.teal,
width: 2.0,
),
),
),
),
child: Text('Submit'),
onPressed: () {},
),