Small update to this question:
First of all, you need to set Jenkins URL
in your system configuration to access such URLs:
Jenkins -> Manage Jenkins -> Configure System -> Jenkins Location -> Jenkins URL
It set to http://localhost:8080/
by default (if you accepted this during initial start of Jenkins)
Optionally specify the HTTP address of the Jenkins installation, such
as http://yourhost.yourdomain/jenkins/. This value is used to let
Jenkins know how to refer to itself, ie. to display images or to
create links in emails.
This is necessary because Jenkins cannot reliably detect such a URL
from within itself.
Then you can access the build or job URLs via BUILD_URL
or JOB_URL
environment variables in your Groovy pipeline script.
For example:
println env.BUILD_URL
println env.JOB_URL
You also can find more such environment variables for your Jenkins instance on this page:
http://localhost:8080/env-vars.html/ (replace localhost:8080
with your Jenkins URL)