This jenkins.domain.tld appears in the answer to a bitbucket pull request builder question.
A search turned up pages mentioning it as a subdomain. What is it exactly? Is that tld something new like the local special domain, or like example.com? If you browse to that domain.tld, nothing is returned.
The referenced SO answer also mentions using http:///. How would that be resolved by DNS or other domain resolution mechanisms to the jenkins server? If putting that into a browser, it redirects to jenkins.com.
tld stands for top level domain : .com, .net, .org, ...
If you want to host your own domain, you'll need to declare your domain.tld (example : jenkins.mydomain.com) in a public or private DNS.