The Process of connecting to a Jenkins agent

Currently, I am using Jenkins agent to connect between GitLab and Jenkins server. I want that every time the server runs, it can automatically connect to the Jenkins server. I have created a service and allowed it to run automatically whenever the server runs. Below is the configuration image of my service. However, when I run it, I tried to log the status and found that it did not work and reported an error. Can you tell me the reason and how to fix it? Thank you for watching and I look forward to your response. If you need any additional information, please message me and I will provide it. Thank you very much
Link image: devops_image - Google Drive