how to use pgrep to find a shell script process

I want to use pgrep command to terminate the running process in centos terminal. I tried: pgrep fedora-proxy-k8s-postgresql | xargs -r kill -9 and I could not found the process because it's a bash script running in background: ➜ pydolphin git:(tencent-cloud) ps aux|grep k8s-pos root 14131 0.0 0.0 113288 1084 ? SN 01:35 0:00 bash ./fedora-proxy-k8s-postgresql.sh What should I do to find and terminate the process using pgrep? Or I have to use ps command?