docs(SDB): update

Author: SamyOubouaziz

serverless/sql-databases/api-cli/postgrest-row-level-security.mdx

@@ -16,7 +16,24 @@ categories:
 - A Scaleway account logged into the [console](https://console.scaleway.com)
 - [Owner](/identity-and-access-management/iam/concepts/#owner) status or [IAM permissions](/identity-and-access-management/iam/concepts/#permission) allowing you to perform actions in the intended Organization
 - [Created a Serverless SQL Database](/serverless/sql-databases/how-to/create-a-database/)
-- [Created two applications](/identity-and-access-management/iam/how-to/create-application/) in IAM
+
+## Add sample data and create PostgreSQL Row Level Security
+
+1. [Connect to your Serverless SQL Database](/serverless/sql-databases/quickstart/#how-to-connect-to-a-database) with a PostgreSQL client such as `psql`:
+    ```bash
+    psql "postgres://[user-or-application-id]:[api-secret-key]@[database-hostname]:5432/[database-name]?sslmode=require"
+    ```
+
+2. Add sample data to the database using the following command:
+    ```sql
+    CREATE TABLE pets (name varchar, keeper varchar, id int);
+    INSERT INTO pets VALUES ('Stuart','role_admin',1),('Nemo','role_admin',2),('Alfie','role_readwrite',3),('Peanut','role_readwrite',4);
+    ```
+
+3. Run the command below to enable **Row Level Security**:
+    ```sql
+    ALTER TABLE pets ENABLE row level security;
+    ```
 
 ## Use Row Level Security with PostgREST