1. Login to Plesk control panel.
2. Select "Firewall" option from "Tools and Settings".
3. Select "Edit Firewall Configuration".
4. Select "Add Custom Rule" from "Tools".
5. Enter the following details.
i. Name of the rule: "Desired name"
ii. Port: "Port you want to enable"
iii.IP address: "Desired IP address"
6. Click "OK" button.