You can specify a custom Whois Server.
Activate the Checkbox to use it.
You can receive the result by Email.
That makes sense if the query would take a long time
(you can query more than hundred servers).
Check the box and enter your Email to use this feature.
Select the TLDs for your query.
If you only need one TLD
you can enter it directly into the domain field (domain.tld).
You should also know that the response time increases
with the number of selected TLD.