Help me in solving GSQ08 problem

My issue

You are allowed to make 1 submissions in 10 seconds on CodeChef… Please help.

My code

/* Write a query to add a column 'Designation' to the table and set 'Null' as the default value. Output the entire table.*/

Alter table employee 
Add column Designation text default null;

select * from employee;

Learning course: Learn SQL
Problem Link: CodeChef: Practical coding for everyone