Your domain availability check should be configured as follows:
- Login to the File manager of your WHMCS folders and navigate to the WHMCS root directory
- Navigate to the a /resources/domains/
- Create a whois.jsonfile in the domains directory.
Add the following the below JSON to the whois.json file.
[
    {
        "extensions": ".ng,.com.ng,.i.ng,.org.ng,.net.ng,.edu.ng,.sch.ng,.gov.ng,.mobi.ng,.name.ng",
        "uri": "socket://whois.nic.net.ng",
        "available": "No Object Found"
    }
]
If you need further assistance kindly open a ticket.
