GitLab default SAST not working

I have configured gitlab-runner (version 16.6) on VM in GCP. I’m using Gitlab-ci pipeline and my application is based on Java (Gradle build).
According to below article, I tried both ways, template and manual but it does not work.

When I use below template, it only print basic information like runner version, start & end time;
template: SAST.gitlab-ci.yml

and when I use the manual process (docker run …) it says project not compatible.