Step 1: Log in to the Plesk panel
Go to https://yourdomain.com:8443 (or the address provided by your hosting provider).

Enter your username and password.

Step 2: Go to "Websites & Domains"
🔍 In the main menu on the left, find "Websites & Domains".
Here you will see all the domains linked to your account.

Step 3: Click "Add Subdomain"
This button is located at the top of the domain list.
📷 Example:

Step 4: Fill in the fields

• Subdomain name – for example, test (this will become test.yourdomain.com).

• Parent domain – select the main domain.

• Document root – for example, test.yourdomain.com, or specify your own path.

📷 Example:

Step 5: Click "OK" or "Create"
After this, the subdomain will be created. You can use it as a separate website or for testing purposes.