Jenkins build not responding to git push

In the Lab - Trivy - Kubernetes, the Jenkins build are not showing when I push the latest changes to Github. I tried running the job manually as instructed on the note section, but it failed within 28ms with no outputs produced in the “Console Output” tab the Jenkins page.

Manual build but failed after 28ms with nothing shown in “Console Output” tab on Jenkins page:

Latest changes are pushed successfully to master branch:

but no build is triggered (except the previous manual build):

I might have missed anything. Any guidance would be much appreciated.

Kind regards,
Henry