Hi @Quang Nguyen,

There might be some credentials/Server IP/Database name you might be entering wrong here.

But you can also try to do it very easily from the Env service center. As you can see in the below-given screenshots.

1. Service center -> Administration -> Database Connection -> Click on the New Database connection

2. Enter all the required fields below.

3. Click on Test Connection and if all the details are correct you will get success on top or get a relevant error for the same.

4. Once the test is successful click on Create button to create the DB connection.

Thanks & Regards

Nitish Kumar

Hello sir

 Kindly follow these below steps in that link sir.
1. Now in Service Studio 11 go to Environment tab and under that click on Environment Management in Service center it will redirect you to a browser. Then Administration and click on Database Connection

2. Click on New Database Connection.

3. Then a screen will appear like this.

4. Enter the credentials and please make sure that the instance name should be entered in the Database field in this screen, which you have create during sql server management studio.

5. Then under Server field , give your system name in that. 

6. Then click on test connection.

7. Once gets finished, if the connection is success, a new Database will be created.

Hope, this one is helpful for you from my side.

Best Regards,
ABHAY KRISHNA GANESH