Installed 'github-autostatus' plugin not u

问题:

Installed https://plugins.jenkins.io/github-autostatus/ plugin

Watches pipeline jobs and provides job and stage stats such as time and pass/fail. Can be configured to update GitHub commit status 
(one status per stage) and send stats to an InfluxDB instance, or StatsD collector, for build health monitoring of job/stage timing and success rate.

As highlighted in link, I am expecting this to appear in stage before PR merge to target button gets enabled. But post plugin installation & restart it's not appearing in PR.s

'Send to GitHub' is selected under 'Autostatus Config' under Jenkins->Configure System

Don't see any difference in behavior when new PR is created against target branch in Github.

Configured 'Poll SCM' to true on this branch to check behavior & build is getting triggered in Jenkins only once 'Merge' is complete, but not when PR is created & Review is pending. Am I missing something to achieve this setup?

Does post build steps in declarative pipeline needs to be added to explicitly updated?. Is there a documentation which details these steps please?.

Don't see configuration instruction on plugin site.